View original document

The full text on this page is automatically extracted from the file linked above and may contain errors and inconsistencies.

Federal Reserve Bank of Chicago

What Determines Bilateral
Trade Flows?
Marianne Baxter and Michael A. Kouparitsas

WP 2005-11

What Determines Bilateral Trade Flows?
Marianne Baxter
Boston University and NBER

Michael A. Kouparitsas
Federal Reserve Bank of Chicago

October 2005

Abstract
This paper undertakes an exhaustive search for robust determinants of international trade, where "robustness" is tested using three popular empirical
methods. The paper is frankly atheoretical: our goal is solely to establish
statistically robust relationships. Along the way, however, we relate our results
to the empirical results obtained by prior researchers and to the received theory
of international trade. We …nd that robust variables include a measure of the
scale of factor endowments; …xed exchange rates; the level of development; and
current account restrictions. Variables that are robust under certain methods
and sample periods include exchange rate volatility, an index of sectoral similarity, and currency union. However, the estimated coe¢ cient on currency
union is much smaller than estimates obtained by prior researchers.
JEL classi…cation: F10, C23, 024
Keywords: Gravity model, Extreme bounds analysis, Factor abundance,
Bilateral trade, Currency union

Marianne Baxter: Department of Economics, Boston University, 270 Bay State Road, Boston
MA 02215, USA (mbaxter@bu.edu). Michael Kouparitsas: Economic Research Department, Federal
Reserve Bank of Chicago, 230 South Lasalle Street, Chicago IL 60604, USA (mkoup@frbchi.org).
The views expressed herein are those of the authors and not necessarily those of the Federal Reserve
Bank of Chicago or the Federal Reserve System.

1

1

Introduction

This investigation undertakes an exhaustive search for robust determinants of international trade, where "robustness" is tested using three popular empirical methods.
The paper is frankly atheoretical: our goal is solely to establish statistically robust
relationships. Along the way, we relate our results to the empirical results obtained
by prior researchers and to the received theories of international trade. However, we
stop well short of testing any particular theory of international trade.
Our dataset includes 92 countries. We collected data on 24 variables that measure
a wide range of economic, geographic, and policy environments. Our data span six
…ve-year intervals from 1970 to 1995. Our list of potential trade determinants includes
the following: the standard gravity variables (distance, common language, common
border, etc.), endowments of the factors of production, including land, labor, and
capital; the level of economic development; various measures of barriers to trade;
exchange rate volatility; currency union; and similarity of industrial structure. We
follow prior research in the measurement of variables insofar as this is possible.
We consider three methods for testing the robustness of the relationship between
bilateral trade and the candidate explanatory variables listed above. First, we employ the method proposed by Leamer (1983, 1985). Second, we employ the method
subsequently proposed by Sala-i-Martin (1997).

Third and …nally, we use an ap-

proach recently suggested by Hendry (1995). We compare the results obtained with
these di¤erent approaches to measuring robustness. We …nd that the Sala-i-Martin
and Hendry approaches are more ‘permissive’than the Leamer method, in the sense
that variables found not to be robust under the Leamer approach can be robust with
the Sala-i-Martin and Hendry approaches. There is no clear ordering between the
Sala-i-Martin and Hendry methods in the sense that variables that are not robust
under one approach can be robust with the other.1
The paper is structured as follows. Section 2 describes our data sources and the
1

Hoover and Perez (2004) …nd, in their study of the determinants of long-term growth, that the
Leamer approach is the least permissive, while the Sala-i-Martin approach is the most permissive.
They show, through Monte-Carlo experiments, that the Leamer approach tends to reject variables
that are in the true model, while the Sala-i-Martin approach tends to include variables that are
not in the true model. This re‡ects size and power distortions associated with these approaches.
The Hendry approach is shown to have near normal size and power, which implies that it includes
variables that are in the true model and rejects those that are not.

2

construction of each of the variables that will be considered as a potential determinant of bilateral trade. Section 3 provides a detailed description of each of the three
empirical methods for determining robustness. Section 4 begins the presentation of
our empirical results with analysis of benchmark econometric models. Speci…cally,
this section presents regressions of trade on gravity variables alone in order to provide a point of comparison for econometric models that include additional regressors.
This section also provides benchmark regressions of bilateral trade on each potential
explanatory variable, one variable at a time. These benchmark regressions are repeated with the set of gravity variables included, in addition to the single additional
explanatory variable.
Section 5 is the heart of the paper, containing the robustness tests for each potential determinant of trade. The results are presented in groups by variable. For each
variable (or group of variables), we present the results and compare our results to
those obtained in the prior literature. We o¤er possible interpretations of the results
in light of received theories of international trade. Section 6 concludes with a brief
summary of our results.

2

Data and Measurement

This section describes the measurement and construction of variables used in this
study. The measure of bilateral trade between countries i and j in period t, Tijt , is
de…ned as follows:
Tijt = ln(Xijt + Xjit )
where Xijt denotes exports from country i to country j in period t.2 The variables
that may explain bilateral trade fall naturally into several distinct groups, as described
below.
2

This speci…cation is motivated by the standard gravity model of bilateral trade and for that
reason is typically the focus of studies of the determinants of trade (see the survey by Rose (2004)).

3

2.1

Gravity variables

The so-called “gravity variables”have been the primary focus of empirical studies of
international trade for over 50 years.3

The gravity variables are included in every

‘robustness’ regression that we run. The reason for the universal inclusion of the
gravity variables is that we wish to determine which variables, in addition to the
gravity variables, can explain bilateral trade. Our gravity variables consist of the
following group:
2.1.1

Distance

The greater is the distance between two countries, the higher are the costs associated
with transporting goods, thereby reducing the gains from trade and reducing trade
itself. We use Glick and Rose’s (2002) estimate of the log of the distance between
two countries.

2.1.2

Common border

Many researchers have shown that the in‡uence of distance on trade is non-linear,
with trade between bordering countries being signi…cantly greater than countries
that are positioned at similar distances, but do not share a border. We use Glick
and Rose’s (2002) indicator variable of common borders, which takes the value 1 if a
country pair shares a border and zero otherwise.
2.1.3

Cultural distance

Measures of ‘cultural distance’ have also been considered as determinants of international trade (see, for example, Glick and Rose (2002)). The most commonly used
measure of ‘cultural distance’is an indicator of common language, which takes the
value 1 if the country pair shares the same language and zero otherwise.
2.1.4

Colonial ties

In recent work, Glick and Rose (2002) investigate the importance of colonial ties for
international trade. They provide two measures of this variable. The …rst measure
3

See Anderson and van Wincoop (2003) for a recent contribution in this area and a comprehensive
list of references.

4

is an indicator variable equal to 1 if the country pair includes a colonizer and one
of its current or past colonies, and is zero otherwise. The second variable is also an
indicator variable, set equal to 1 for country pairs that had the same colonizer.
2.1.5

Economic scale

Empirical gravity models have shown that measures of economic scale are important
determinants of bilateral trade. We follow much of the empirical literature by including the log of the product of the two countries’levels of GDP as a scale variable
in the group of gravity variables. The inclusion of population is also widespread in
the empirical trade determinants literature. In many cases, it is included indirectly
through the natural logarithm of the product of countries’per capita levels of GDP.
We therefore include per capita GDP as an additional measure of economic scale.

2.2

Factor Endowments

A country’s factor endowments are thought to be important determinants of the
country’s pattern of trade. The longstanding belief in the importance of factor endowments is a consequence of the widespread acceptance of the Heckscher-Ohlin
model of international trade.

Speci…cally, the Heckscher-Ohlin theory predicts that

country pairs should trade more, the more di¤erent are their factor endowments.
There is a voluminous literature that bears on the importance of factor endowments for international trade, and we will mentioned only a few contributions to this
literature in order to motivate the inclusion of the factor endowment variables in our
investigation.

Early empirical investigations based on the Heckscher-Ohlin theory

were quite negative; the classic paper is by Bowen, Leamer, Sveikauskas (1987). More
recently, Frankel, Stein and Wei (1995, Table 4), in their study of regional trading
blocks, …nd weak to no support for the Heckscher-Ohlin hypothesis. Frankel, Stein
and Wei include, along with other variables di¤erences in capital-labor ratios, educational attainment and land-labor ratios in a standard gravity equation. They …nd
that the coe¢ cients on these variables are positive as predicted by the theory but
are not statistically signi…cant. In contrast, a recent study by Yamarik and Ghosh
(2005) …nds that di¤erences in per capita land are positively related to bilateral
trade ‡ows and are robust to the inclusion of other variables in their dataset, while
di¤erences in educational attainment and capital-labor ratios are signi…cant in their
5

base regressions, but fragile to the inclusion of indicators of stage of development.
Recent papers by Debaere (2003) and Romalis (2004) also …nd strong empirical support for Rybczynski and Heckscher-Ohlin predictions on factor abundance and factor
content.
We measure the endowments of three factors of production: human capital, physical capital, and land. The details of the measurement of these variables is summarized
below.
2.2.1

Human capital

We use a measure of human capital as our measure of labor input. Human capital is
measured using the Barro-Lee (1996, 1997) data on average years of schooling in the
population over age 15. We construct two measures of human capital in a bilateral
setting. The …rst is the log of the product of education in the two countries, where
Fit stands for the factor endowment in country i in period t:
Factor Intensity Measure 1: ln(Fit Fjt )

(1)

This variable has not been used in prior studies of the determinants of bilateral
trade. We included it in our investigation because we viewed it as an indicator of
the ‘scale’of human capital in the two countries, similar to the way that the product
of GDP measures is a scale variable in the standard gravity equation. Obviously,
this measure is higher the higher is human capital in either of the two countries. But
another interesting aspect of this measure is that it is higher the more equal are the
levels of human capital in the two countries, holding …xed the aggregate amount of
human capital in the country pair.
Our second measure of human capital is more commonly used, and is given by the
log of the ratio of the highest to the lowest levels of education in the two countries:
Factor Intensity Measure 2: ln[max(Fit ; Fjt )= min(Fit ; Fjt )]

(2)

This indicator has been used in a number of empirical trade studies, including those
discussed earlier.
2.2.2

Physical capital

In parallel with our measure of human capital, we construct two measures of a country’s endowment of physical capital per worker, using data from Easterly and Levine
6

(2001). The …rst measure is the log of the product of physical capital per worker in
the two countries; the second is the absolute value of the log of the ratio.
2.2.3

Land

Our measure of land is arable land per capita, since we feel that arable land is more
closely related to a country’s productive capacity than is total land. We construct
two measures of bilateral land variables, in parallel with the measures for human and
physical capital described above.

2.3

Stage of development

The levels of development within the two countries that comprise a country pair
may a¤ect trade within the country pair. Following IMF classi…cations reported in
the World Economic Outlook (2000) we split countries into two groups, “developed
countries”and “developing countries". We then construct an indicator variable that
takes on the value 1 if both countries are from the same group, and zero otherwise.4
Theory alone is not de…nite on the sign of the relationship between this variable and the extent of bilateral trade. On the one hand, the “New View” of international trade developed by Helpman and Krugman (1985) stressed the large and
growing trade between developed countries, with the bulk of this trade occurring in
goods produced under monopolistic competition. On the other hand, Ricardian and
Heckscher-Ohlin-Samuelson models would predict more trade between countries that
are di¤erent from one another.
Frankel, Stein and Wei (1995), Thursby and Thursby (1987) and Yamarik and
Ghosh (2005) measure relative development as di¤erences in log real per capita GDP.
Yamarik and Ghosh use two additional measures. The …rst is di¤erences in the share
of manufacturing in total GDP, the idea being that more developed countries should
have larger manufacturing shares. The second is di¤erences in the share of manufacturing in total merchandise trade. We approach the measurement of industrial
structure more directly by constructing an index of industrial similarity (de…ned below) …rst suggested by Shea (1996).
4

Because of constraints imposed by the inclusion of the country …xed e¤ects, we cannot separately
identify (i) a coe¢ cient for a pair of two developed countries and (ii) a coe¢ cient for a pair of
developing countries.

7

Frankel, Stein and Wei (1995), Thursby and Thursby (1987) and Yamarik and
Ghosh (2005) …nd that di¤erences in per capital GDP enter the gravity model with a
negative sign. All 3 measures used by Yamarik and Ghosh had estimated coe¢ cients
whose signi…cance levels were sensitive to the inclusion of other variables. No clear
conclusion could therefore be drawn.
The absolute level of development in a country pair is typically measured as the
log of the product of per capita GDPs. Although the size of its coe¢ cient estimates
vary across studies, this measure of absolute development positively, and statistically
signi…cantly related to explaining bilateral trade. The Yamarik and Ghosh (2005)
analysis includes the average share of manufacturing in GDP and average share of
manufacturing in merchandise exports. They …nd that both variables are robust,
each with a positive sign.
With the exception of Klein and Shambaugh (2004), we did not …nd studies that
look at discrete indicators of the stage of development. Klein and Shambaugh run
separate regressions for industrial-industrial, industrial-developing, and developingdeveloping pairs. There is some variation in coe¢ cient estimates across these bilateral
pairs, but no clear pattern of results emerges from their study.

2.4

Industrial similarity

We explore the importance of the stage of development on bilateral trade from another
angle by comparing the industrial structure of bilateral trading partners. We use the
following measure of industrial similarity suggested by Shea (1996):
N
X

sin sjn

i=n

ISIij = v
v
u
u N
uX
N
uX
u
t
s2in t
s2jn
i=n

(3)

i=n

where sin is industry n’s share of country i’s GDP. This indicator takes on values
between 0 and 1. If a bilateral pair have the same sectoral structure this indicator
is 1. The indicator takes on the value zero if both countries are specialized in
production, i.e., sin = 0 whenever sjn > 0.

8

2.5

Impediments to ‡ows of goods and capital

There are a wide range of explicit trade barriers used by the countries in our dataset.
They can be roughly broken down into two groups. The …rst group measures barriers
to ‡ows of goods. Most of these barriers are non-tari¤ barriers, such as quotas, which
explicitly limit the ‡ows of goods. Tari¤ barriers are typically levied as an ad valorem
tax (i.e., proportional to the value of an imported good). Due to data limitations,
most prior studies of the determinants of bilateral trade have not used explicit measures of ad valorem tari¤s or tari¤-equivalent estimates of non-tari¤ barriers. In some
cases, researchers have used country-speci…c or country-pair …xed e¤ects to capture
these trade barriers. In general, summary measures of trade liberalization are used,
such as indicator variables that are one if country pairs are members of a free trade
area and zero otherwise.
The Klein and Shambaugh (2004) study estimates the relationship between membership of a regional free trade area and bilateral trade ‡ows. They …nd that, on
average, members of free trade areas have trade ‡ows that are 50 percent higher than
trading partners that are not part of a free trade area. Ghosh and Yamarik (2004)
use a large set of indicator variables that are speci…c to membership in a particular free trade area (e.g., NAFTA) in their Bayesian extreme bounds analysis of free
trade areas. They …nd that the relationship between this large set of regional free
trade agreements and bilateral trade is fragile. We follow this approach by employing Glick and Rose’s (2002) indicator variable that captures all free trade areas and
customs unions. This variable takes the value 1 if such an agreement exists between
the bilateral pair during the sample period, and 0 otherwise.
The second set of trade barriers deals with restrictions on capital ‡ows or current account transactions. Perturbations of a country’s capital/…nancial account has
e¤ects on the country’s current and future trade ‡ows. For example, factors that
restrict capital ‡ows may restrict the size of the current account and net export balance. Therefore, current account restrictions may be an important determinant of
the level of trade between countries.
2.5.1

Multiple exchange rate arrangements

There are numerous exchange rate arrangements employed by the countries in our
dataset.

These arrangements range from (i) membership in a currency union (in

9

which the members share the same legal tender and monetary policy, as in the European Monetary Union) to (ii) a policy under which the exchange rate is determined
by market forces (as in the United States). In some cases, countries have multiple
exchange rate arrangements. For example, Nigeria has four exchange rates: (i) the
o¢ cial exchange rate which results from auctions of foreign exchange by the Nigerian
Central Bank; (ii) the interbank rate at which commercial banks transact among
themselves; (iii) the retail "bureau de change" rate; and (iv) the parallel market rate.
We explore the extent to which these multiple arrangements are barriers to trade.
Speci…cally, we construct an indicator variable using data from Milesi-Ferretti (1998)
that takes the value 2 if both countries have multiple exchange rate arrangements,
takes the value 1 if only one country has a multiple exchange rate arrangement and
is zero otherwise.5
2.5.2

Controls on current account transactions

Many countries place restrictions on current account transactions. These restrictions
a¤ect, among other things, (i) the way in which payments must be made on merchandise and service imports and (ii) the repatriation of proceeds of merchandise
and service exports. These restrictions can also a¤ect ‘invisible’transactions, such as
(i) investment related transactions (interest, pro…ts/dividends, and rent/lease payments), and (ii) payments to non-resident labor. We explore the extent to which these
restrictions on current account transactions a¤ect bilateral trade ‡ows by employing
an indicator variable takes the value 2 if both countries impose controls, 1 if only one
country imposes controls, and zero otherwise.
2.5.3

Speci…c surrender requirements

Countries sometimes impose “speci…c surrender” requirements on proceeds from
exports or invisible transactions when these transactions exceed a speci…ed value or
if the transaction involves particular goods or services. In most cases, the exporter
must surrender the proceeds from a transaction to the monetary authority which
exchanges the proceeds at a regulated rate of exchange. This type of arrangement
is common in countries that have adopted a currency board. For example, during
the period under which Argentina had a currency board, surrender requirements
were imposed on export proceeds exceeding $200,000. We assess the impact of the
5

We are grateful to Dr. Milesi-Ferretti for sharing his data with us.

10

restrictions on bilateral trade by using an indicator variable takes the value 2 if both
countries have speci…c surrender requirements, 1 if only one country does, and is zero
otherwise.
2.5.4

Controls on the capital account

Most countries employ some form of capital control that regulates the inward and
outward ‡ow of capital. These restrictions include prohibitions; need for prior approval, authorization and noti…cation; discriminatory taxes; reserve requirements;
interest penalties; and limits on the holding of assets at home by non-residents and
abroad by residents. We explore the implications of these controls for bilateral trade
by employing an indicator variable that takes the value 2 if both countries impose
capital controls, 1 if only one country imposes capital controls, and zero otherwise.

2.6

Currency Union

There is much current interest in determining the e¤ect of currency union on trade.
Indeed, one important reason for forming a currency union is the promotion of trade
within the union. Consequently, there is a large literature on the e¤ects of currency
union on trade.6 Most studies indicate a positive e¤ect of currency union on trade,
so it is a natural candidate for our investigation of robust determinants of bilateral
trade. Because a currency union can be explicit (a shared currency or a formal treaty)
or implicit (a unilateral …xing of the exchange rate), we construct two measures of
currency union.
2.6.1

Explicit and implied currency union

We employ an indicator variable constructed by Glick and Rose (1992) that takes on
the value 1 if the country pair is part of an explicit or implied currency union. In an
explicit currency union, the currency of one country circulates in the second country
as the sole legal tender. Alternatively, the two countries may both be members of a
union in which the same legal tender is shared by the members of the union. Adopting
such systems generally requires the complete surrender of monetary policy to another
6

This literature is summarized in Rose (2004).

11

nation’s monetary authority (US Federal Reserve in the case of "dollarization") or
an independent international monetary authority (ECB, for EMU members).
Implied currency unions are de…ned as situations in which at least one of the two
countries maintains a formal exchange rate peg to another country’s currency. This
may take the form of a currency board arrangement. A less restrictive alternative
is a conventional peg in which a country agrees to peg its currency at a …xed rate to
another currency or a basket of currencies. Implied unions do not include crawling
pegs, crawling bands, horizontal bands or managed ‡oating arrangements since they
allow the bilateral rate of exchange to vary over time.
2.6.2

Fixed exchange rate

We constructed an indicator that takes the value 1 if the country pair maintained a
constant monthly nominal exchange rate during a …ve year interval, and 0 otherwise.
This variable includes all explicit and implicit currency unions, as well as informal
pegging arrangements and any other policy that, ex post, meant that the exchange
rate between the two countries did not vary during the sample. This variable is
obviously broader than the variable used by Glick and Rose. We include this variable
because we wish to investigate whether the formal nature of the currency unions
selected by the Glick/Rose variable are more strongly related to bilateral trade than
this alternative, broader measure.

2.7

Exchange Rate Variability

There are numerous exchange rate arrangements employed by the countries in
our dataset, as discussed above.

The wide range of exchange-rate policies implies

wide variation in the levels of exchange-rate volatility among the country pairs in
our dataset. According to theoretical analyses, the relationship between exchange
rate volatility and bilateral trade is ambiguous and typically depends on the source
of exchange rate ‡uctuations (see, for example Bacchetta and van Wincoop (2000),
and Sercu and Uppal (2003)).
The empirical literature is less ambiguous.

There is a large body of empirical

research which …nds that higher exchange rate volatility is associated with lower trade
volumes. Klein and Shambaugh (2004) , in their comprehensive analysis of the e¤ect
of …xed versus ‡oating exchange rates on trade ‡ows, …nd that direct exchange rate
pegs have a statistically signi…cant positive relationship with the volume of bilateral
12

trade ‡ows. In contrast, they …nd that indirect pegs do not have a statistically
signi…cant relationship with trade ‡ows.7 Exchange rate volatility is explored further
in their paper by including an indicator of the level and square of the volatility of
bilateral exchange rates, where volatility is measured as the standard deviation of
monthly exchange rates over a …xed period. They …nd that the level of exchange
rate volatility has a statistically signi…cant negative relationship with trade ‡ows.
However, Tenreyro (2004) argues that Klein and Shambaugh use econometric methods
that lead to biased estimates. She argues that, in the absence of these biases,
exchange rate volatility does not have a signi…cant impact on trade ‡ows.
Although the jury is still out on the empirical importance of exchange rate variability as a determinant of trade volumes, it deserves inclusion in our study.

We

therefore investigate the importance of exchange rate volatility on trade ‡ows using
a measure of exchange rate volatility de…ned as the standard deviation of the growth
rate of the nominal monthly bilateral exchange rate over the preceding …ve-year period.

3

Methodology

The goal of this paper is to determine which economic variables are important determinants of bilateral trade. To accomplish this, we employ three methods that
have been proposed as appropriate for isolating robust relationships. This section
describes these three methods.

3.1

The “Extreme Bounds Analysis” (EBA) of Leamer

This sub-section describes the extreme-bounds analysis (EBA) suggested by Leamer
(1983). The general form of the regression used for the EBA is follows. The variable
Tijt measures log bilateral trade between countries i and j in period t:
Tijt =

A Aijt

+

M Mijt

+

Z Zijt

+ vijt :

(4)

The independent variables are of three types, as follows. A denotes a set of
variables that appear in every regression, thus these are referred to as "always included
7

An indirect peg is de…ned as follows. If countries A and B have explicit pegs with C, then A
and B have an indirect peg. To take another example, if A is pegged to B, and B is pegged to C,
then A and C have an indirect peg.

13

variables". This set may be empty. In our application, however, A includes the
gravity variables. M is the variable which is being tested for robustness. Z contains
one or more other variables that prior studies have suggested may be an important
determinant of bilateral trade ‡ows. The EBA is performed by varying the set of
variables included in Z for a particular M -variable. Following Levine and Renelt
(1992), we include three Z-variables in each regression, drawn from the complete set
of potential Z-variables, denoted C. Let N denote maximum number of sets of three
Z-variables that can be drawn from C. The extreme bounds of an M -variable are
established by ordering from lowest to highest the 90 percent con…dence intervals of
the N estimates of

M

from the exhaustive set of Z-variable draws from C. We will

say that an M -variable is robust if the lower and upper bounds of this ordering are
the same sign.

3.2

The “Extreme Bounds Analysis” of Sala-i-Martin

Sala-i-Martin (1997) proposed an alternative application of the extreme-bounds
concept. Sala-i-Martin’s methodology is derived from Leamer’s (1983) EBA methodology and uses the same regression model (4). However, Sala-i-Martin’s approach
di¤ers in the way the extreme bounds of the variable of interest are calculated. In
this case, the extreme bounds of an M -variable are based on a weighted average of
the N point estimates of M from the exhaustive set of Z-variable draws from C.
Let bM n denote the estimate of M from regressing bilateral trade on the Avariables, on the variable M , and on the nth Z-variable, Zn . Let ! n denote the
weight (de…ned below) attached to the estimate
point estimate of

M

M n.

Then the Sala-i-Martin’s

from this set of N regression models is de…ned as:
b

M

N
X
n=1

! n bM n :

(5)

The weights, ! n , are constructed as follows. Let LM n denote the likelihood function
of the regression model evaluated at bM n ; T; M and Zn . The weight ! n is then
computed as

!n

LM n
:
PN
n=1 LM n

14

(6)

The variance of bM is computed as follows:
b

2

M

N
X
n=1

! n b2 M n

(7)

where b2 M n is the estimated variance of bM n . According to Sala-i-Martin’s approach,
an M -variable is robust if the t-statistic of bM exceeds the critical value associated
with the researcher’s desired level of signi…cance.

3.3

The “General to Speci…c” approach of Hendry

We use a version of Hendry’s (1995) general-to-speci…c approach. Our method begins
with a regression of the dependent variable (i.e., log bilateral trade) on all potential
explanatory variables. Next we break the set of explanatory variables into two
groups: a set S of variables with statistically signi…cant coe¢ cients; and the set of
remaining variables, N S, with coe¢ cients that are not statistically signi…cant, which
includes a variable, L, with the lowest t-statistic. After partitioning the variables in
this way we drop the variable L and regress the dependent variable on the remaining
set of explanatory variables. If there is a new L-variable, we drop it from the set of
explanatory variables and regress the dependent variable on the further reduced set
of explanatory variables. This process repeats until there are no variables in N S.

4

Benchmark Results

This section begins the presentation of the results of our empirical investigation. We
present …rst the results for the gravity variables alone, as a benchmark for comparison
with the results of including other variables. Next, we present regressions for each
potential explanatory variable, with one variable per regression. Finally, we combine
the gravity variables with the other potential explanatory variables, introducing the
additional explanatory variables one at a time.

4.1

Gravity variables only

We begin our investigation with estimation of the e¤ects of the gravity variables on
trade:
15

Tijt = Dijt +

A Aijt

+ vijt

(8)

where Tijt is bilateral trade between countries i and j, Dijt is a matrix of country and
year …xed e¤ects, and Aijt is the vector of gravity variables. Since we have data on
one important variable–sectoral similarity–only for a subset of countries, throughout
the paper we run each regression for the full sample and again for the restricted
sample. The results are shown in Table 1-A (full sample) and Table 1-B (restricted
sample).
The results are, for the most part, independent of the sample and have the expected sign.

For example, distance has a negative coe¢ cient:

countries located

closer to each other trade more. A common border and a common language are
associated with higher trade. Trade is higher if the two countries had a common
colonizer or are in a colonial relationship. There is a negative estimated coe¢ cient on
the variable indicating a current colonial relationship, but this variable is not signi…cant. The log product of GDP is positive and signi…cant in both samples. However,
the log product of per capita GDP is positive and signi…cant in the full sample, but
negative and not signi…cant in the restricted sample.

4.2

Other variables only

Next, we explore the importance of the non-gravity variables–our “M-variables”–in
explaining bilateral trade when considered one at a time. We run the following
regression for each M-variable, including in each regression country and year …xed
e¤ects, denoted Dijt :
Tijt = Dijt +

M Mijt

+ vijt :

(9)

Table 2 summarizes the results from these regressions. As in the case of Table
1, there are two panels corresponding to the large sample (which includes all available data) and the restricted sample (which includes only observations for which the
sectoral similarity variable can be constructed). The results are similar across the
two panels.

Beginning with measure 1 for factor intensity (see equation (1), we

…nd that education and capital per worker are both signi…cantly related to bilateral
trade. This means that trade is higher between country pairs for which the products
of endowments of human and physical capital are higher. By contrast, measure 1 for
16

arable land per worker is not signi…cant in the full sample, although it is signi…cantly
less than zero in the restricted sample.
Measure 2 of the factor intensity variables measures the di¤erence between factor
endowments in the two countries–see equation (2). Here, we …nd that education, capital, and arable land are all signi…cantly, negatively related to bilateral trade. Thus,
the more dissimilar are the two countries in terms of all three factor endowments, the
less they trade.
The development-indicator variable takes on the value 1 if both countries are at
the same stage of development: either both are developed countries or both are
developing countries.8

This indicator is strongly signi…cant across both samples.

The variable measuring industrial similarity, which is 1 if countries have identical
sectoral shares and zero if they have no similarities, is positive and signi…cant in
the smaller sample. Thus, countries trade more, the more similar is the industrial
structure in the two countries.
We considered four measures of capital controls. In the full sample, each measure
of controls carries a negative estimated coe¢ cient, although only two are signi…cantly
di¤erent from zero: (i) multiple exchange rates and (ii) restrictions on the current
account.

In the restricted sample, only the variable measuring restrictions on the

current account is signi…cant–the coe¢ cient is negative, as in the full sample. These
…ndings suggest that most types of capital controls have little e¤ect on bilateral trade,
even when considered in isolation. The only variable that has a signi…cant e¤ect
across both samples is the variable measuring restrictions on the current account.
This is quite understandable, as this restriction is directly targeting bilateral trade.
The full-sample coe¢ cient of 0.09 means that trade is 9% lower if one country of
the pair under consideration has trade restrictions, and trade is 2*0.09=0.18 or 18%
lower if both countries have current account restrictions. In economic terms, this is
a very signi…cant e¤ect.
We turn next to measures of currency union. A large and growing literature
has found that currency union is associated with higher trade among members of
the union. Our measure of currency union is the same measure used in Glick and
Rose (2002). This variable has a signi…cant, positive coe¢ cient in both the large and
restricted samples. We also include the ‘…xed exchange rate’variable de…ned earlier–
8

Because we include country and year …xed e¤ects, we cannot independently estimate the e¤ects
of “two developed countries” and “two developing countries.”

17

this variable takes on the value 1 if the pair of countries had a …xed exchange rate
over the sample period, regardless of whether there was an explicit currency union
or currency board in place. This variable is also signi…cantly, positively related to
bilateral trade.
Membership in a customs union is signi…cantly, positively related to trade in
both samples, as one would expect and as policymakers hope is the case when they
establish a customs union or free trade area. Finally, bilateral exchange rate volatility
is negatively, signi…cantly related to trade. This result adds weight to the theoretical
and empirical literatures that argue exchange rate volatility lowers bilateral trade.

4.3

Combining gravity and ‘other’variables

Next, we explore the importance of the non-gravity variables–our “M-variables”–in
explaining bilateral trade when considered one at a time in a regression that also
includes the gravity variables, Aijt . We run the following regression for each Mvariable, including country and year …xed e¤ects, Dijt , in each regression:
Tijt = Dijt +

A Aijt

+

M Mijt

+ vijt

(10)

Table 3 summarizes the results from these regressions. As in the case of Table 1
there are two panels, corresponding to the large sample (which includes all available
data) and the restricted sample (which includes only observations for which the sectoral similarity variable can be constructed). The results are broadly similar across
the two panels.
Our main …ndings are as follows. Measure 1 of the capital and education variables
remain positive and signi…cant, although the estimated coe¢ cient on capital per
worker is much smaller once the gravity variables are included. None of the measure
2 factor intensity variables is signi…cant, although all three were signi…cantly negative
in Table 2 in which the gravity variables were omitted.
The indicator for same stage of development is now negative and strongly signi…cant–
recall this variable was signi…cantly, positively related to trade in Table 2. Evidently
there are important interactions between this variable and one or more of the gravity
variables.

The results for the capital controls are similar to the results in Table

2–in fact, the coe¢ cient estimates are larger when the gravity is included. Thus, restrictions on the current account are still signi…cantly, negatively related to bilateral

18

trade.
The coe¢ cients on the currency union variable and the …xed exchange rate variable
are still positive and signi…cant, although the size of the coe¢ cients is much smaller
once the gravity variables are included. For example, in Table 2 the full-sample
estimate of the currency union coe¢ cient was 2.62, but falls to 0.47 once the gravity
variables are included (Table 3).

Similarly, the full-sample estimate of the …xed-

exchange-rate variable was 1.90 in Table 2, but is only 0.43 in Table 3.
The customs union variable is no longer signi…cant once the gravity variables are
included–it was positive and signi…cant in Table 2. The measure of exchange rate
volatility also loses statistical signi…cance when the gravity variables are included.
Table 3-B contains results for the sectoral similarity variable. The coe¢ cient is
negative and statistically signi…cant when the gravity variables are included. This
means that countries trade less, the more similar are their industrial structures. Recall that, in Table 2, the coe¢ cient was positive and statistically signi…cant, implying
more trade the more similar are industrial structures.
Overall, we …nd that only a few variables retain their statistically signi…cant relationship to bilateral trade once the gravity variables are included. Of those that
remain signi…cant, several had estimated coe¢ cients that are markedly smaller once
gravity is taken into account. The development indicator and the sectoral similarity
variable are both still signi…cant once gravity variables are included, but the sign
of the coe¢ cients change from negative to positive. Our conclusion from this section is that the statistical signi…cance of economic determinants of trade is strongly
in‡uenced by the inclusion of gravity variables.

5

Results: Robustness

In this section, we study each group of variables in turn, discussing their ‘robustness’
and how this varies across the three empirical methodologies. Robustness the three
approaches are contained in three tables, corresponding to the approaches of Leamer
(Table 4), Sala-i-Martin (Table 5), and Hendry (Table 6). Table 7 summarizes our
results, showing which variables and methods lead to …ndings of robustness for speci…c
variables.

19

5.1

Factor Endowments

We consider three factors: human capital (education); physical capital per worker;
and arable land. As discussed in Section 2, we have two measures of each variable: see
equations (1) and (2). Our baseline results in the prior section showed that measure
1 for education and capital-per-worker were signi…cantly, positively related to trade
even when gravity variables were taken into account. Measure 2 was signi…cant only
for some variables and some sample periods.
The results for the Leamer approach are shown in shown in Table 4.

As with

previous tables, there are separate panels for the full sample (Panel A) and for the
restricted sample (Panel B). In the full sample, measure 1 for education, capital-perworker, and arable-land-per-worker are robustly, positively related to bilateral trade.
None of the measure 2 variables is signi…cant. The results for the restricted sample
are similar, with the exception that measure 1 for arable land is no longer robust. In
general, the Leamer test is considered the most restrictive of the robustness tests, so
we are interested to learn how our results change when we consider other tests.
The results for the Sala-i-Martin test is reported in Table 5. These results are
the same as the Leamer results, with just one exception: measure 2 for capital-perworker is now robust (with a negative coe¢ cient), although only in the full sample
and only with a 10% signi…cance level.
The Hendry results are reported in Table 6. Measure 1 for education and capitalper-worker are robust, as they were with the Leamer and Sala-i-Martin tests. Measure
1 for arable land is not robust with the Hendry approach, although it was robust in
the full sample with both prior tests. The Hendry results di¤er from Leamer and
Sala-i-Martin for the measure-2 variables. In the large sample, all three endowment
measures are signi…cant: education and land carry positive coe¢ cients, while capital
has a negative coe¢ cient. In the small sample, only capital per worker is robust,
and continues to have a negative coe¢ cient.
Overall, our results indicate that measure 1 endowment variables, which measure
the product of the endowments, are robust, especially human capital and physical
capital. There is less support for the measure-2 variables, which measure di¤erences
in endowments, and which have been the traditional variables included in studies
of the determinants of trade.

Thus, our results have apparently uncovered a new

measure of factor endowments which has signi…cant role in explaining (in a statistical
sense) bilateral trade. This measure, being the product of endowments in the two
20

countries, is higher the higher is the sum of endowments in the two countries. Holding
…xed the level of the sum of endowments, this measure is higher the more equal are
the endowments across the two countries.

5.2

Development indicator

We considered the stage of development as a possible determinant of international
trade. Since our focus is on bilateral trade, our development indicator takes on the
value 1 if the two countries share the same level of development (either developed or
developing), and takes on the value 0 if one country is developed while the other is
developing.9 Economic theory is largely silent on the potential importance of development levels as determinants of trade volume. However, our empirical investigation
suggests that the level of development is strongly associated, in a statistical sense,
with bilateral trade. We turn now to the results.
Tables 2A and 2B gives the baseline estimates for the development indicator coe¢ cient for the full and restricted samples. In both sample periods the coe¢ cient
estimate is positive and signi…cantly di¤erent from zero. However, Table 3 shows that
the point estimates in both samples become negative and signi…cant when the gravity
variables are added to the regression of bilateral trade on the development indicator:
the baseline estimates are -0.61 in the large sample, and -0.63 in the restricted sample.
Evidently, the development indicator is correlated with some variables in the set of
gravity variables, and the coe¢ cient estimate for development is thus highly sensitive
to the inclusion of the gravity variables.
Table 4 presents robustness tests using the Leamer method. In both samples, the
development indicator is robust and has a negative coe¢ cient. This means that, other
things held constant, a pair of countries at the same level of development experiences
less bilateral trade than a pair of countries with di¤ering levels of development.
It is plausible that the level of development might be highly correlated with the
sectoral structure of economic activity.

For example, highly developed economies

tend to produce and trade manufactured goods, while developing countries tend to
produce and trade agricultural goods and commodities. Thus, it is notable that the
presence of the variable that measures industrial similarity (ISI) in Table 4-B does
not reduce the signi…cance of the development variable.
9

The industrial similarity

Because of the presence of country and year …xed e¤ects, it is not possible to separately estimate
coe¢ cients for (i) two developed countries and (ii) two developing countries.

21

variable, by contrast is not robust, as we discuss further in the next sub-section.
Tables 5 and 6 present robustness results for the Sala-i-Martin and Hendry methods. With both methods and for both sub-samples, the development indicator continues to be robust with a negative coe¢ cient. Further, the coe¢ cient estimates are
very similar to those obtained with the Leamer approach. Overall, the results are
very clear for the development variable: other things held constant, two countries at
a similar level of development have lower bilateral trade.

5.3

Industrial Similarity

Industrial structure has long played an important role in theories of international
trade.

Although theories di¤er on the determinants of production and trade, the

central questions investigated by theoretical and empirical studies of international
trade remain “who produces what” and “who trades what.” Therefore, we constructed a variable that measures similarity in two countries’ industrial structures
and investigate the importance of industrial structure as a determinant of bilateral
trade. Unfortunately, the necessary data for computation of the sectoral similarity
variable is available only for a subset of country pairs. This reduces our sample from
10947 observations to 7274 observations. Thus, we present results throughout for
the full sample (Tables 2A through 7A) and for the restricted sample for which the
sectoral similarity variable can be computed (Tables 2B through 7B).
Table 2B shows that sectoral similarity is positively, signi…cantly related to bilateral trade when considered on its own (together with country and year …xed e¤ects.)
Table 3B, however, shows that the inclusion of the gravity variables changes this result dramatically: the coe¢ cient estimate for sectoral similarity is now signi…cantly
negative.
The robustness results are as follows.

With the Leamer approach (Table 4B),

the sectoral similarity variable has a negative and signi…cant coe¢ cient (-0.58) in the
baseline case, but the variable is not robust. With the less restrictive Sala-i-Martin
approach, the sectoral similarity variable continues to carry a negative coe¢ cient (0.45) and is found to be robust. Sectoral similarity is also found to be robust under
the Hendry approach, with a coe¢ cient estimate of -0.71.
Overall, our …ndings indicate that similarity of the sectoral structure of production
is negatively related to bilateral trade: country pairs with similar patterns of production trade less than country pairs for which the pattern of production di¤ers between
22

the two countries.

These …ndings lend support to theories of international trade

which highlight country-level di¤erences as important for trade (e.g., the Ricardian
and Heckscher-Ohlin theories), and cast doubt on theories that predict that trade
will rise with increased industrial similarity (e.g., the theory presented in Helpman
and Krugman (1989)).

5.4

Capital controls

We turn next to investigation of the importance of policies that directly or indirectly
interfere with international trade. As described in Section 2, we consider four policies:
(i) multiple exchange rate arrangements; (ii) restrictions on current account transactions; (iii) restrictions on capital account transactions; and (iv) speci…c surrender
requirements.
The baseline univariate regressions, reported in Table 2, can be summarized as
follows. In the large sample, both (i) multiple exchange rates and (ii) restrictions
on the current account, have a signi…cant (negative) e¤ect on bilateral trade. In the
restricted sample, only current account restrictions are signi…cant. When the gravity
variables are included (Tables 3A-B), only the variable measuring current account
restrictions continues to be signi…cantly, negatively related to bilateral trade. This is
true for both samples. The signi…cance of this variable is easy to understand, since
current account restrictions, in their various forms, are all designed to a¤ect external
trade.
But are these restrictions robust?

Table 4 reports that the current account

restrictions are robustly, negatively related to bilateral trade in both sample periods.
None of the other capital controls considered is robust. The Sala-i-Martin and Hendry
approaches con…rm the …ndings of the Leamer approach–the estimated coe¢ cients
for current account restrictions are negative and robust. Across all of these methods,
the point estimates of the coe¢ cient lies in the range -0.08 to -0.12. Thus, if one of
the two countries has current account restrictions trade is reduced by 8%-12%, while
if both countries have current account restrictions, trade is reduced by 16%-25%.

5.5

Fixed Exchange Rates and Currency Union

One of the most compelling arguments for currency union and other …xed-exchangerate arrangements is that these arrangements facilitate international trade by remov-

23

ing exchange-rate uncertainty.

Fixed exchange rate arrangements may be made

through public announcements and codi…ed through explicit currency union, or they
may be more informal through …xing arrangements that are not part of a publicly
announced exchange-rate policy.
We attempt to distinguish between these two types of arrangements in the following way. We say that a pair of countries has …xed exchange rates vis-a-vis each other
if the bilateral exchange rate does not change over the course of the 5-year sample
period. This de…nition thus includes both explicit and implicit …xing arrangements.
A subset of these country pairs is engaged in an explicit currency union, and we code
this arrangement separately by assigning to the currency union variable the value 1 to
country pairs in a currency union, and the value 0 to country pairs not in a currency
union, even if they have …xed exchange rates.
There are only 48 observations out of a possible 10947 in which there is a currency
union. (A particular country pair can appear as an ‘observation’more than once if
the currency union was in place for more than one …ve-year period). There are 131
additional observations in which there is a …xed exchange rate for the country pair
for that sample period, but for which there was no currency union, either explicit
or implicit.

The country pairs in our sample that have currency union or a …xed

exchange rate are concentrated mainly in two groups. The …rst group, accounting for
17 of the 49 observations, is characterized by a large, developed country paired with
a less-developed country (e.g., the US paired with Panama, Dominican Republic,
and Guatemala, for a total of 13 observations); and the UK paired with Ireland,
Cypress, and Malawi, for a total of 4 observations).

The second group consists

of pairs of developing countries, primarily African countries. The second group
includes a few cases in which a country pair has an implied union through each of
these countries’ currency union with the US. Aside from this, the remaining 26
observations are country pairs from the group that includes Togo, Cameroon, Benin,
Senegal, Barbados, Mali, and Guyana.
There are many more country pairs for which there is a …xed exchange rate but
no explicit or implicit currency union. However, these country pairs typically do not
involve two developed countries. The only example in which two OECD countries
had a …xed bilateral exchange rate for one or more 5-periods is the US-Mexico. Thus,
we suggest great caution be exercised in interpreting the results of our investigation
as shedding light on the potential results of currency union between developed coun24

tries. More bluntly, our results may not have much to say about the trade e¤ects
of the European Monetary Union. Since our data is the same as data used by prior
researchers, a similar caution may apply to interpretation of results obtained in this
prior work.
5.5.1

Currency union

The currency union variable takes on the value 1 if the country pair has an explicit
currency union, and zero otherwise.

Thus, the currency union variable selects a

subset of the country pairs that had a value of 1 for the …xed-exchange-rate variable.
Frankel and Rose (2000, Table 1) report a coe¢ cient in the range 1.22-1.72 in a
regression of bilateral trade on gravity variables and the currency union variable,
which they report is consistent with the earlier estimate of Rose (2000), and is also
consistent with Glick and Rose (2002).
Under the Leamer approach, currency union is fragile. Although the baseline
point estimates are 0.47 (large sample) and 0.71 (restricted sample), the standard
errors of these estimates are large enough that the estimates are barely signi…cant
in the baseline case, and are fragile when we allow for combinations of Z-variables.
Under the Sala-i-Martin approach, by contrast, currency union is robust, although
just barely so. In the large sample, the coe¢ cient estimate is 0.44 with a standard
error of 0.22. With the restricted sample, the estimate is 0.66 with a standard error
of 0.32. The point estimates are thus similar to those obtained under the Leamer
approach, and are much smaller than the estimates obtained by Frankel and Rose
(2000). The less-restrictive nature of the Sala-i-Martin approach leads to a result
of robustness, with t-statistics of about 2.05, while the Leamer approach …nds that
currency union is not robust. Turning to the Hendry approach, we …nd that currency
union does not appear as a robust determinant of bilateral trade in either sample.
Overall, our results cast serious doubt on the hypothesis that currency union
plays an important, independent role in determining bilateral trade. The signi…cant
role of the currency union variable uncovered by previous studies is not robust to the
inclusion of other variables. Of course, this is a purely statistical result and it is
possible that currency union is important for bilateral trade but in a way that is too
subtle to be detected using these methods.

25

5.5.2

Fixed exchange rate

The …xed-exchange-rate variable takes on the value 1 if the country pair has an
exchange rate that does not change during the sample period.

This will include

both explicit currency unions and informal …xing arrangements.

Looking …rst at

the Leamer approach, the baseline coe¢ cient estimate for the …xed exchange rate
variable is 0.43 for the large sample, and is found to be robust. In the restricted
sample, however, the baseline point estimate is 0.30 with a standard error of 0.16,
and is therefore not robust.
Turning to the Sala-i-Martin approach, we …nd that …xed-exchange-rate variable
is robust in both the large and the restricted samples, with coe¢ cient point estimates
of 0.42 and 0.27, respectively. With the Hendry approach, the …xed exchange rate
variable is signi…cant in the large sample. as it was with the Leamer approach. The
point estimate is 0.30 with a standard error of 0.12. In the restricted sample, however,
the …xed-exchange-rate variable is not signi…cant, which again is what was found with
the Leamer approach.
Overall, the …xed-exchange-rate variable is robust with all methods in the large
sample, but is only robust under the Sala-i-Martin approach in the restricted sample.
In all cases, the coe¢ cient estimate is in the range 0.25-0.45, with standard errors
about 0.12-0.16.

5.6

Free trade areas/customs union

The next variable considered is an indicator variable that takes on the value 1 if
the country pair was in a free trade area or customs union. Theory would predict
a positive relationship between the level of bilateral trade and the existence of a
customs union, since the object of a customs union is to enhance trade within the
union by reducing trade barriers among members. It is surprising, therefore, that
our robustness analysis gives a very mixed view of the relationship between free trade
areas and the level of bilateral trade.
Beginning with the Leamer method, we …nd that the free trade area variable is
not robust. This is true whether one considers the large sample or the restricted
sample. Further, the point estimates in the baseline cases are actually negative–we
expected a positive coe¢ cient.

Using the Sala-i-Martin method, we …nd that the

free trade area variable has a positive, but fragile coe¢ cient in the full-sample and a

26

robust negative coe¢ cient in the small sample. Turning to the Hendry approach, the
free trade area variable has a positive coe¢ cient and is robust in the full sample, but
is fragile in the small sample.

5.7

Exchange rate volatility

Exchange rate volatility is widely believed to reduce bilateral trade, as it adds an
additional source of price uncertainty to goods sold abroad. Our baseline regressions
in Table 2 supported this view:

the coe¢ cient estimate ranges from -0.63 (large

sample) to -0.82 (restricted sample) and are strongly signi…cant in both samples.
When the gravity variables are included (Table 3), the coe¢ cient estimates are still
negative, but are much smaller in absolute value and are no longer stastistically
signi…cant.
The robustness results are as follows. With the Leamer approach, as shown in
Table 4, the baseline estimates for exchange rate volatility are negative but insignificant, implying that exchange-rate volatility is not robust in either sample.

The

Sala-i-Martin and Hendry approaches yield similar results: exchange rate volatility
is not robust in the large sample, although it is robust in the restricted sample. In
the restricted sample, however, the robustness result is not strong, in the sense that
the t-statistic is -1.70 with the Sala-i-Martin approach (the normal CDF is 0.96), and
is -1.69 with the Hendry approach. Thus the …nding of robustness would not hold
if the test were more stringent with, for example, a 1% signi…cance level. Overall,
we …nd that exchange rate volatility is robustly, negatively related to trade, but this
…nding of robustness is not strong, relying as it does on particular methods, particular
sample periods, and particular signi…cance levels.

6

Conclusion

This paper was intended to be a purely empirical investigation, attempting to draw
together several methods for assessing robustness, and applying these methods a
longstanding question: “What determines international trade?” We attempted to
be quite inclusive in our approach to selecting variables as potential determinants of
international trade. In this concluding section, we will simply summarize the salient
results. For reference, we have collected all the robustness results into a single table,
Table 7.
27

First, we …nd that one particular measure of bilateral factor endowments are
robust determinants of trade.

Speci…cally, the product of endowments in the two

countries is positively related to bilateral trade. Holding …xed the level of the sum
of endowments, trade is higher the more equal are the endowments across the two
countries. This measure had not generally been included in prior studies of the
empirical determinants of international trade. The more commonly-used measure,
involving bilateral di¤erences in factor endowments, was not robust.
Second, we found that bilateral trade was lower if two countries shared the same
stage of development, and that this result is robust across all three methods. Bilateral
trade was also found to be lower the more similar are industrial structures in the
country pair: this variable was not robust with the Leamer approach but was robust
with the Hendry and Sala-i-Martin approaches. We studied a variety of capital
controls, and found that the only robust restriction was restriction on current account
transactions which, as expected, is negatively related to trade.
We explored the importance of currency union and also the importance of a …xed
exchange rate (which includes currency unions). We found that …xed exchange rates
were positively related to bilateral trade, but were robust only in the full sample
(and in the restricted sample under the Sala-i-Martin approach).

The results for

currency union were weaker: although the point estimates of the coe¢ cients were
always positive, they were robust only under the Sala-i-Martin approach. Further,
the point estimates of the coe¢ cient on currency union were much smaller than those
reported in earlier research.
The results on customs unions are mixed. This variable has a positive coe¢ cient
and is robust under the Hendry method in the full sample, but in the restricted sample
the coe¢ cient estimate is negative and is robust only for the Sala-i-Martin approach.
It is impossible to draw any conclusions from this pattern of results. Finally, there is
weak evidence that exchange rate volatility is negatively related to trade. Although
the coe¢ cient point estimates are negative, as is consistent with prior research, the
variable is robust only in the restricted sample.

28

References
[1] Anderson, James and Eric van Wincoop (2003) “Gravity with Gravitas:

A

Solution to the Border Puzzle," American Economic Review 93(1) March , 17092.
[2] Bacchetta, Philippe and Eric van Wincoop (2000) “Does Exchange-Rate Stability Increase Trade and Welfare?”American Economic Review 90(5) December ,
1093-1109.
[3] Barro, Robert and Jong-Wha Lee (1996) “Schooling Quality in a Cross Section
of Countries, AER, Papers and Proceedings, 86(2) (May 1996), 218-223.
[4] Barro, Robert and Jong-Wha Lee (1997) “International Measures of Schooling
Years and Schooling Quality", National Bureau of Economic Research Working
Paper 6198, September 1997.
[5] Bowen, Harry; Edward Leamer and Leo Sveikauskas, “Multicountry, Multifactor
Tests of the Factor Abundance Theory,”American Economic Review 1987, 791809.
[6] Debaere, Peter (2003) "Relative Factor Abundance and Trade" Journal of Political Economy 11, 589-610.
[7] Easterly, William and Ross Levine (2001) “It’s Not Factor Accumulation: Stylized Facts and Growth Models,”World Bank Economic Review 15(2), 177-219.
[8] Feenstra, Robert C. (2000) "World Trade Flows, 1980-1997" University of
California-Davis, Institute for Government A¤airs Working Paper, March 2000.
[9] Feenstra, Robert C., Robert E. Lipsey and Harry Bowen (1997), "World Trade
Flows, 1970-1992, with Production and Tari¤ Data" National Bureau of Economic Research Working Paper 5910, January 1997.
[10] Frankel, Je¤rey, Ernesto Stein and Shang-Jin Wei, 1995, "Trading Blocs and
the Americas: The Natural, the Unnatural and the Supernatural" Journal of
Development Economics 47, 61-95.

29

[11] Frankel, Je¤rey and Andrew Rose (2002) “An Estimate of the E¤ect of Currency
Unions on Trade and Output,” Quarterly Journal of Economics CXVII.2, 437466.
[12] Gosh, Sucharita and Steven Yamarik (2004) "Are Regional Trading Arrangements Trade Creating? An Application of Extreme Bounds Analysis" Journal
of International Economics 63, 369-395.
[13] Glick, Reuven and Andrew Rose (2002) “Does a Currency Union A¤ect Trade?
The Time Series Evidence," European Economic Review 46(6), 1125-1151.
[14] Helpman, Elhanan and Paul R. Krugman (1989) "Trade Policy and Market
Structure" MIT Press (Cambridge, MA).
[15] Hendry, David (1995) Dynamic Econometrics, Oxford University Press, Oxford,
United Kingdom.
[16] Hoover, Kevin and Stephen Perez (2004) “Truth and Robustness in Crosscountry Growth Regressions," Oxford Bulletin of Economics and Statistics 66(5),
765-798.
[17] International Monetary Fund (2000) " World Economic Outlook" October 2000.
[18] Klein, Michael and Jay C. Shambaugh (2004) "Fixed Exchange Rates and Trade"
National Bureau of Economic Research Working Paper 10696, August 2004.
[19] Leamer, Edward (1983) "Let’s Take the Con Out of Econometrics" American
Economic Review 73(1), 31-43.
[20] Leamer, Edward (1985) "Sensitivity Analysis Would Help" American Economic
Review 75(3), 308-313.
[21] Levine, Ross and David Renelt (1992) “A Sensitivity Analysis of Cross-country
Growth Regressions,”American Economic Review 82(4), 942-963.
[22] Milesi-Ferretti, Gian-Maria (1998) “Why Capital Controls? Theory and Evidence”in: Eij¢ nger, S., and Huizinga, H., Positive Political Economy: Theory
and Evidence. Cambridge University Press, Cambridge, England., 217-247.
[23] Penn World Tables, Version 5.6, University of Pennsylvania.
30

[24] Rose, Andrew (2000) “One Money, One Market? The E¤ect of Common Currencies on International Trade,”Economic Policy 30, 7-33.
[25] Rose, Andrew (2004) “A Meta-Analysis of the E¤ect of Common Currencies
on International Trade,”National Bureau of Economic Research Working Paper
10373, March 2004.
[26] Rose, Andrew and Je¤rey Frankel (2004) “Estimating the E¤ect of Currency
Unions on Trade and Output," National Bureau of Economic Research Working
Paper 7857, August 2000.
[27] Sala-i-Martin, Xavier (1997) “I have Just Run Two Million Regressions,”American Economic Review 87(2), 178-183.
[28] Sercu, Piet and Raman Uppal (2003) "Exchange Rate Volatility and International Trade: A General Equilibrium Analysis" European Economic Review 47
[29] Shea, John (1996) "Comovements in Cities" Carnegie Rochester Conference Series on Public Policy 44, 169-206.
[30] Tenreyro, Silvana (2004) "On the Trade Impact of Nominal Exchange Rate
Volatility" Federal Reserve Bank of Boston Working Paper.
[31] Thursby, Jerry and Marie C. Thursby (1987) "Bilateral Trade Flows, the Linder
Hypothesis, and Exchange Risk" The Review of Economics and Statistics 69(3),
488-495.
[32] United Nations Industrial Development Organization (2000) "Industrial Statistics Database, 3-Digit Level of ISIC (Rev.2) 1963-1998 on CD ROM".
[33] United Nations Statistical Division (2001) "Statistical Yearbook, Forty Seventh
Issue on CD ROM".
[34] Yamarik, Steven and Sucharita Gosh (2005) "A Sensitivity Analysis of the Gravity Model" The International Trade Journal 19(1), 83-126.
[35] World Bank (1998) "World Development Indicators on CD ROM".

31

Table 1: Gravity Variables Only
Includes Country and Year Fixed Effects

Variables
Distance (DIST)
Common Border (BRDR)
Common Language (LANG)
Common Colonizer (COMCOL)
Current Colony (CURCOL)
Colonial Relationship (COLONY)
GDP (GDP)
Per Capita GDP (GDPPC)

β
-1.26
0.32
0.71
0.27
-0.84
1.03
0.83
0.39

A. Full Sample
10947 observations
se(β)
t-stat R-sq.
0.02
-51.47 0.81
0.11
3.00
0.05
15.30
0.07
3.71
0.59
-1.43
0.09
11.39
0.13
6.46
0.13
3.01

B. Restricted sample
7274 observations
β
se(β)
t-stat R-sq.
-1.28 0.03
-42.44 0.82
0.30 0.13
2.27
0.66 0.06
11.71
0.47 0.09
5.22
-0.86 0.59
-1.45
1.21 0.11
10.59
1.09 0.16
6.72
-0.04 0.17
-0.21

Table 2-A: Basic Regressions including one M-Variable, Country and Year Fixed Effects
Large Sample: No Sectoral Similarity
Variable Group
"M-Variable" (abbreviation)
Factor Intensity, Measure 1: Education (EDUC1)
Log[Fi*Fj]
Capital per Worker (CAP1)
Arable Land Per Worker (LAND1)

β
0.50
0.84
-0.11

se(β)
0.11
0.07
0.10

t-stat.
4.59
12.73
-1.04

R-sq
0.72
0.72
0.72

Factor Intensity, Measure 2: Education (EDUC2)
Log[Max(Fi, Fj)/Min(Fi, Fj)] Capital per Worker (CAP2)
Arable Land Per Worker (LAND2)

-0.60
-0.31
-0.11

0.05
0.02
0.03

-11.38
-17.20
-4.04

0.72
0.73
0.72

0.36

0.04

8.72

0.72

-0.09
-0.09
-0.01
-0.04

0.04
0.04
0.05
0.05

-2.22
-2.23
-0.16
-0.98

0.72
0.72
0.72
0.72

Development Indicator

Same Stage of Development (DEV)

Capital Controls

Multiple Exchange Rates (CC1)
Restrictions on Current Account (CC2)
Restrictions on Capital Account (CC3)
Specific Surrender Requirements (CC4)

Currency Union

Fixed exchange rate (FE)
Currency Union (CU)

1.90
2.62

0.14
0.26

13.56
10.24

0.72
0.72

Customs Union

Free Trade Area or Equivalent (FTA)

2.46

0.12

20.08

0.73

Financial

Bilateral Exchange Rate Volatility (ERV)

-0.63

0.07

-8.52

0.72

Table 2-B: Basic Regressions including one M-Variable, Country and Year Fixed Effects
Restricted Sample: Includes Sectoral Similarity
β
se(β) t-stat.
Variable Group
"M-Variable" (abbreviation)
0.79
0.14
5.56
Factor Intensity, Measure 1: Education (EDUC1)
0.76
0.08
9.31
Log[Fi*Fj]
Capital per Worker (CAP1)
-0.41
0.14
-2.99
Arable Land Per Worker (LAND1)
Factor Intensity, Measure 2: Education (EDUC2)
Log[Max(Fi, Fj)/Min(Fi, Fj)] Capital per Worker (CAP2)
Arable Land Per Worker (LAND2)

R-sq
0.74
0.74
0.73

-0.53
-0.25
-0.09

0.07
0.02
0.03

-7.73
-11.35
-3.03

0.74
0.74
0.73

0.28
0.98

0.05
0.20

5.62
4.88

0.74
0.74

-0.08
-0.12
0.04
0.04

0.05
0.05
0.06
0.06

-1.47
-2.30
0.74
0.72

0.73
0.73
0.73
0.73

Development Indicator

Same Stage of Development (DEV)
Sectoral Similarity (ISI)

Capital Controls

Multiple Exchange Rates (CC1)
Restrictions on Current Account (CC2)
Restrictions on Capital Account (CC3)
Specific Surrender Requirements (CC4)

Currency Union

Fixed exchange rate (FE)
Currency Union (CU)

1.08
2.49

0.19
0.38

5.59
6.48

0.74
0.74

Customs Union

Free Trade Area or Equivalent (FTA)

1.79

0.16

11.04

0.74

Financial

Bilateral Exchange Rate Volatility (ERV)

-0.82

0.11

-7.78

0.74

Table 3-A: Regressions including one M-Variable, Gravity Variables, Country and Year Fixed Effects
Large Sample: No Sectoral Similarity
Variable Group
"M-Variable" (abbreviation)
Factor Intensity, Measure 1: Education (EDUC1)
Log[Fi*Fj]
Capital per Worker (CAP1)
Arable Land Per Worker (LAND1)

β
0.57
0.30
0.17

se(β)
0.10
0.07
0.09

t-stat.
5.97
4.52
1.79

R-sq
0.81
0.81
0.81

Factor Intensity, Measure 2: Education (EDUC2)
Log[Max(Fi, Fj)/Min(Fi, Fj)] Capital per Worker (CAP2)
Arable Land Per Worker (LAND2)

0.07
0.01
2.46E-03

0.05
0.02
0.02

1.47
0.88
0.11

0.81
0.81
0.81

Development Indicator

Same Stage of Development (DEV)

-0.57

0.04

-15.58

0.81

Capital Controls

Multiple Exchange Rates (CC1)
Restrictions on Current Account (CC2)
Restrictions on Capital Account (CC3)
Specific Surrender Requirements (CC4)

-0.02
-0.08
0.01
0.02

0.04
0.03
0.04
0.04

-0.67
-2.55
0.35
0.57

0.81
0.81
0.81
0.81

Currency Union

Fixed exchange rate (FE)
Currency Union (CU)

0.43
0.47

0.12
0.22

3.61
2.19

0.81
0.81

Customs Union

Free Trade Area or Equivalent (FTA)

-0.01

0.11

-0.07

0.81

Financial

Bilateral Exchange Rate Volatility (ERV)

-0.04

0.07

-0.68

0.81

Table 3-B: Regressions including one M-Variable, Gravity Variables, Country and Year Fixed Effects
Restricted Sample: Includes Sectoral Similarity
Variable Group
"M-Variable" (abbreviation)
Factor Intensity, Measure 1: Education (EDUC1)
Log[Fi*Fj]
Capital per Worker (CAP1)
Arable Land Per Worker (LAND1)
Factor Intensity, Measure 2: Education (EDUC2)
Log[Max(Fi, Fj)/Min(Fi, Fj)] Capital per Worker (CAP2)
Arable Land Per Worker (LAND2)

β
se(β)
0.62
0.13
0.28
0.08
0.10
0.14

t-stat.
4.85
3.28
0.74

R-sq
0.82
0.82
0.82

0.12
0.05
1.42E-02

0.06
0.02
0.02

2.11
2.38
0.57

0.82
0.82
0.82

Development Indicator

Same Stage of Development (DEV)
Sectoral Similarity (ISI)

-0.61
-0.58

0.04
0.17

-13.69
-3.39

0.82
0.82

Capital Controls

Multiple Exchange Rates (CC1)
Restrictions on Current Account (CC2)
Restrictions on Capital Account (CC3)
Specific Surrender Requirements (CC4)

-0.04
-0.13
0.00
0.02

0.04
0.04
0.05
0.05

-0.95
-3.03
-0.03
0.47

0.82
0.82
0.82
0.82

Currency Union

Fixed exchange rate (FE)
Currency Union (CU)

0.30
0.71

0.16
0.32

1.86
2.20

0.82
0.82

Customs Union

Free Trade Area or Equivalent (FTA)

-0.58

0.14

-3.99

0.82

Financial

Bilateral Exchange Rate Volatility (ERV)

-0.16

0.09

-1.69

0.82

Table 4-A: Robust regression using Leamer Approach
Large Sample: Industrial Similarity Variable Not Included
Variable Group
"M-Variable" (abbreviation)
Factor Intensity, Measure 1: Education (EDUC1)
Log[Fi*Fj]

Capital per Worker (CAP1)

Arable Land Per Worker (LAND1)

Factor Intensity, Measure 2: Education (EDUC2)
Log[Max(Fi, Fj)/Min(Fi, Fj)]

Capital per Worker (CAP2)

Arable Land Per Worker (LAND2)

Development Indicator

Same Stage of Development (DEV)

β
0.70
0.57
0.45

se(β)
0.10
0.10
0.10

t-stat.
6.99
5.97
4.43

R-sq
0.81
0.81
0.82

ZVAR1 ZVAR2 ZVAR3
LAND2 EDUC2
FE
DEV

EDUC2

CAP2

0.33
0.30
0.16

0.07
0.07
0.07

4.91
4.52
2.27

0.81
0.81
0.82

LAND2

CAP2

FE

DEV

EDUC1

CAP2

0.25
0.17
0.15

0.09
0.09
0.09

2.67
1.79
1.66

0.81
0.81
0.81

EDUC1

CAP1

ERV

EDUC1

CC2

CC2

0.17
0.07
-0.18

0.05
0.05
0.05

3.56
1.47
-3.82

0.81
0.81
0.82

EDUC1

CAP1

FE

DEV

LAND1

FTA

0.03
0.01
-0.16

0.02
0.02
0.02

1.83
0.88
-8.76

0.81
0.81
0.82

EDUC1

CAP1

FE

DEV

CAP1

FTA

0.03
0.00
0.00

0.02
0.02
0.02

1.31
0.11
-0.01

0.82
0.81
0.81

DEV

LAND1

CAP1

EDUC1

CAP1

CU

-0.59
-0.57
-0.80

0.04
0.04
0.04

-15.15
-15.58
-18.26

0.82
0.81
0.82

EDUC1

EDUC2

FE

CAP2

CC2

FTA

Robust/
Fragile
Robust

Robust

Robust

Fragile

Fragile

Fragile

Robust

Table 4-A (continued): Robust regression using Leamer Approach
Large Sample: Industrial Similarity Variable Not Included
Variable Group
Capital Controls

"M-Variable" (abbreviation)
Multiple Exchange Rates (CC1)

Restrictions on Current Account (CC2)

Restrictions on Capital Account (CC3)

Specific Surrender Requirements (CC4)

Currency Union

Fixed exchange rate (FE)

Currency Union (CU)

Customs Union

Financial

Free Trade Area or Equivalent (FTA)

Bilateral Exchange Rate Volatility (ERV)

β
0.02
-0.02
-0.03

se(β)
0.04
0.04
0.04

t-stat.
0.60
-0.67
-0.86

R-sq
0.81
0.81
0.81

ZVAR1 ZVAR2 ZVAR3
CAP1
CC2
FE
LAND1

CC4

CU

-0.06
-0.08
-0.10

0.03
0.03
0.03

-1.97
-2.55
-2.93

0.81
0.81
0.82

EDUC1

EDUC2

FE

DEV

CAP2

CC4

0.04
0.01
-0.01

0.04
0.04
0.05

1.00
0.35
-0.17

0.81
0.81
0.81

CAP1

CC2

FE

LAND1

CAP1

CC4

0.06
0.02
0.00

0.04
0.04
0.04

1.43
0.57
0.05

0.81
0.81
0.81

CAP1

CC2

FE

EDUC1

CAP2

CC3

0.49
0.43
0.26

0.12
0.12
0.12

4.08
3.61
2.19

0.81
0.81
0.82

EDUC1

EDUC2

CAP1

DEV

CAP2

CC2

0.54
0.47
0.10

0.22
0.22
0.22

2.50
2.19
0.45

0.81
0.81
0.82

EDUC1

EDUC2

CAP1

DEV

CAP2

ERV

0.41
-0.01
-0.02

0.11
0.11
0.11

3.68
-0.07
-0.14

0.82
0.81
0.81

DEV

CAP2

CU

EDUC1

CAP1

FE

0.02
-0.04
-0.10

0.07
0.07
0.07

0.31
-0.68
-1.52

0.81
0.81
0.82

EDUC1

CC2

FE

DEV

LAND1

CAP1

Robust/
Fragile
Fragile

Robust

Fragile

Fragile

Robust

Fragile

Fragile

Fragile

Table 4-B: Robust regression using Leamer Approach
Restricted Sample: Industrial Similarity Variable Included
Variable Group
"M-Variable" (abbreviation)
Factor Intensity, Measure 1: Education (EDUC1)
Log[Fi*Fj]

Capital per Worker (CAP1)

Arable Land Per Worker (LAND1)

Factor Intensity, Measure 2: Education (EDUC2)
Log[Max(Fi, Fj)/Min(Fi, Fj)]

Capital per Worker (CAP2)

Arable Land Per Worker (LAND2)

Development Indicators

Same Stage of Development (DEV)

Industrial Similarity Index (ISI)

β
0.75
0.62
0.47

se(β)
0.13
0.13
0.13

t-stat.
5.69
4.85
3.52

R-sq
0.82
0.82
0.83

0.33
0.28
0.16

0.09
0.08
0.08

3.88
3.28
1.89

0.17
0.10
0.04

0.14
0.14
0.14

0.22
0.12
-0.26

ZVAR1 ZVAR2 ZVAR3
LAND1 EDUC2
FTA
DEV

EDUC2

CAP1

0.82
0.82
0.83

CAP2

CC4

ERV

DEV

EDUC1

CAP2

1.20
0.74
0.27

0.82
0.82
0.83

EDUC1

CAP2

CAP1

DEV

CAP2

CC2

0.06
0.06
0.06

3.57
2.11
-4.15

0.82
0.82
0.83

EDUC1

CU

ERV

DEV

LAND2

CC2

0.06
0.05
-0.20

0.02
0.02
0.03

3.02
2.38
-7.38

0.82
0.82
0.83

EDUC1

CAP1

CU

DEV

ERV

ISI

0.04
0.01
0.01

0.02
0.02
0.02

1.52
0.57
0.44

0.83
0.82
0.82

DEV

EDUC1

CAP2

EDUC2

CAP1

ISI

-0.61
-0.61
-0.84

0.05
0.04
0.05

-12.61
-13.69
-15.28

0.83
0.83
0.83

CU

FTA

ISI

EDUC2

CAP2

ISI

0.12
-0.58
-0.78

0.18
0.17
0.21

0.67
-3.39
-3.74

0.83
0.82
0.83

DEV

LAND2

CC2

DEV

EDUC2

CAP2

Robust/
Fragile
Robust

Robust

Fragile

Fragile

Fragile

Fragile

Robust

Fragile

Table 4-B (continued): Robust regression using Leamer Approach
Restricted Sample: Industrial Similarity Variable Included
Variable Group
Capital Controls

"M-Variable" (abbreviation)
Multiple Exchange Rates (CC1)

Restrictions on Current Account (CC2)

Restrictions on Capital Account (CC3)

Specific Surrender Requirements (CC4)

Currency Union

Fixed exchange rate (FE)

Currency Union (CU)

Customs Union

Financial

Free Trade Area or Equivalent (FTA)

Bilateral Exchange Rate Volatility (ERV)

β
0.02
-0.04
-0.05

se(β)
0.05
0.04
0.05

t-stat.
0.38
-0.95
-1.10

R-sq
0.82
0.82
0.82

-0.12
-0.13
-0.15

0.05
0.04
0.04

-2.53
-3.03
-3.36

0.82
0.82
0.83

0.03
0.00
-0.04

0.05
0.05
0.06

0.56
-0.03
-0.69

0.82
0.82
0.82

0.07
0.02
-0.01

0.05
0.05
0.05

1.33
0.47
-0.11

0.82
0.82
0.82

0.33
0.30
0.14

0.16
0.16
0.16

2.03
1.86
0.89

0.76
0.71
0.31

0.32
0.32
0.32

-0.04
-0.58
-0.60
-0.10
-0.16
-0.21

ZVAR1 ZVAR2 ZVAR3
EDUC1 CAP1
CC2
LAND1

CC4

ISI

CC1

ERV

ISI

DEV

CAP2

CC4

CAP1

CC2

ERV

CAP1

CC4

FTA

CAP1

CC2

FE

EDUC1

EDUC2

ISI

0.82
0.82
0.83

LAND1

CAP1

ISI

DEV

CAP2

CC2

2.36
2.20
0.98

0.82
0.82
0.83

CAP2

CAP1

CC2

DEV

CAP2

ERV

0.15
0.14
0.14

-0.24
-3.99
-4.15

0.83
0.82
0.82

DEV

CAP2

ISI

EDUC1

CAP1

ERV

0.09
0.09
0.09

-1.03
-1.69
-2.24

0.82
0.82
0.83

EDUC1

CC2

FE

DEV

CAP1

CC4

Robust/
Fragile
Fragile

Robust

Fragile

Fragile

Fragile

Fragile

Fragile

Fragile

Table 5-A. Robust Determinants of International Trade: Sala-i-Martin Approach
Large Sample: Sectoral Similarity Variable Not Included

0.57
0.29
0.19

se(β)
0.10
0.07
0.09

t-stat
5.91
4.34
2.01

Normal
CDF
1.00
1.00
0.98

Factor Intensity, Measure 2 Education
Log[Max(Fi, Fj)/Min(Fi, Fj)] Capital per Worker
Arable Land Per Worker

0.04
-0.02
0.01

0.05
0.02
0.02

0.93
-1.26
0.34

0.82
0.90
0.63

Fragile
Robust
Fragile

Development Indicator

Same Stage of Development

-0.63

0.04

-16.17

1.00

Robust

Capital Controls

Multiple Exchange Rates
Current Account Restrictions
Capital Account Restrictions
Specific Surrender Requirements

-0.01
-0.08
0.02
0.03

0.04
0.03
0.04
0.04

-0.38
-2.47
0.38
0.67

0.65
0.99
0.65
0.75

Fragile
Robust
Fragile
Fragile

Currency Union

Fixed Exchange Rate
Currency Union

0.42
0.44

0.12
0.22

3.52
2.05

1.00
0.98

Robust
Robust

Customs Union

Free Trade Area or Equivalent

0.08

0.11

0.73

0.77

Fragile

Financial

Exchange Rate Volatility

-0.04

0.07

-0.64

0.74

Fragile

Variable Group
Factor Intensity, Measure 1
Log[Fi*Fj]

Independent Variables
Education
Capital per Worker
Arable Land Per Worker

β

Robust/
Fragile
Robust
Robust
Robust

Table 5-B. Robust Determinants of International Trade: Sala-i-Martin Approach
Restricted Sample: Sectoral Similarity Variable Included
Normal
Independent Variables
t-stat CDF
β
se(β)
Variable Group
Factor Intensity, Measure 1
Education
0.63
0.13
4.88
1.00
Log[Fi*Fj]
Capital per Worker
0.28
0.08
3.32
1.00
Arable Land Per Worker
0.11
0.14
0.81
0.79
Factor Intensity, Measure 2
Log[Max(Fi, Fj)/Min(Fi, Fj)]

Education
Capital per Worker
Arable Land Per Worker

Development Indicators

Robust/
Fragile
Robust
Robust
Fragile

0.05
0.00
0.02

0.06
0.02
0.02

0.77
-0.02
0.72

0.78
0.51
0.76

Fragile
Fragile
Fragile

Same Stage of Development
Industrial Similarity Index

-0.66
-0.45

0.05
0.18

-13.79
-2.49

1.00
0.99

Robust
Robust

Capital Controls

Multiple Exchange Rates
Current Account Restrictions
Capital Account Restrictions
Specific Surrender Requirements

-0.03
-0.13
0.00
0.03

0.05
0.04
0.05
0.05

-0.64
-2.93
-0.10
0.58

0.74
1.00
0.54
0.72

Fragile
Robust
Fragile
Fragile

Currency Union

Fixed Exchange Rate
Currency Union

0.27
0.66

0.16
0.32

1.70
2.04

0.96
0.98

Robust
Robust

Customs Union

Free Trade Area or Equivalent

-0.47

0.15

-3.25

1.00

Robust

Financial

Exchange Rate Volatility

-0.16

0.09

-1.70

0.96

Robust

Table 6: Robust Determinants of International Trade: Hendry Approach
A. Large Sample: Sectoral Similarity Variable Not Included
Significant Independent Variables
t-stat R-sq.
β
se(β)
Education, Measure 1
0.55
0.10
5.45 0.82
Capital per Worker, Measure 1
0.15
0.07
2.25
Education, Measure 2
0.11
0.06
1.96
Capital per Worker, Measure 2
-0.16
0.02
-7.77
Arable Land per Worker, Measure 2
0.22
0.09
2.42
Same Stage of Development
-0.78
0.04
-17.48
Restrictions on Current Account
-0.07
0.03
-2.28
Fixed Exchange Rate
0.30
0.12
2.54
Free Trade Area or Equivalent
0.40
0.11
3.55

B. Restricted Sample: Sectoral Similarity Variable Included
Significant Independent Variables
t-stat R-sq.
β
se(β)
Education, Measure 1
0.54
0.13
4.27 0.83
Capital per Worker, Measure 1
0.16
0.08
1.86
Capital per Worker, Measure 2
-0.19
0.03
-6.84
Same Stage of Development
-0.81
0.05
-14.92
Sectoral Similarity
-0.71
0.21
-3.41
Restrictions on Current Account
-0.12
0.04
-2.79
Exchange Rate Volatility
-0.16
0.09
-1.69

Table 7-A: Summary of Results
Large Sample: Industrial Similarity Variable Not Included
Variable group
Specific Variable
Factor Intensity Variables: Education
Capital per Worker
Log[Fi*Fj]
Arable Land per Worker

Leamer
0.57 *
0.30 *
0.17 *

Sala-i-Martin
0.57 *
0.29 *
0.19 *

Hendry
0.55 *
0.15 *
0.22 *

Factor Intensity Variables: Education
Log[Max(Fi, Fj)/Min(Fi, Fj)] Capital per Worker
Arable Land per Worker

0.07
0.01
0.00

0.04
-0.02 **
0.01

0.11 *
-0.16 *
--

Development Indicator

Countries at Same Stage of Development

-0.57 *

-0.63 *

-0.78 *

Capital Controls

Multiple Exchange Rates
Restrictions on Current Account Transactions
Restrictions on Capital Account Transactions
Specific Surrender Requirements

-0.02
-0.08 *
0.01
0.02

-0.01
-0.08 *
0.02
0.03

--0.07 *
---

Currency Union

Fixed Exchange Rate
Currency Union

0.43 *
0.47

0.42 *
0.44 *

0.30 *
--

Customs Union

Free Trade Area or Equivalent

-0.01

0.08

0.40 *

Financial Variables

Bilateral Exchange Rate Volatility

-0.04

-0.04

--

Notes: * indicates variable is robust at 5% level of statistical significance
** indicates variable is robust at 10% level of statistical significance
-- indicates variable is eliminated in general to specific reduction

Table 7-B: Summary of Results
Restricted Sample: Industrial Similarity Variable Included
Variable group
Specific Variable
Factor Intensity Variables: Education
Log[Fi*Fj]
Capital per Worker
Arable Land per Worker

Leamer
0.62 *
0.28 *
0.04

Sala-i-Martin
0.63 *
0.28 *
0.11

Hendry
0.54 *
0.16 *
--

Factor Intensity Variables: Education
Log[Max(Fi, Fj)/Min(Fi, Fj)] Capital per Worker
Arable Land per Worker

0.12
0.05
0.01

0.05
0.00
0.02

--0.19 *
--

Development Indicators

Countries at Same Stage of Development
Industrial Similarity

-0.61 *
-0.58

-0.66 *
-0.45 *

-0.81 *
-0.71 *

Capital Controls

Multiple Exchange Rates
Restrictions on Current Account Transactions
Restrictions on Capital Account Transactions
Specific Surrender Requirements

-0.04
-0.13 *
0.00
0.02

-0.03
-0.13 *
0.00
0.03

--0.12 *
---

Currency Union

Fixed Exchange Rate
Currency Union

0.30
0.71

0.27 *
0.66 *

---

Customs Union

Free Trade Area or Equivalent

-0.58

-0.47 *

--

Financial

Bilateral Exchange Rate Volatility

-0.16

-0.16 *

-0.16 *

Notes: * indicates variable is robust at 5% level of statistical significance
** indicates variable is robust at 10% level of statistical significance
-- indicates variable is eliminated in general to specific reduction

Working Paper Series
A series of research studies on regional economic issues relating to the Seventh Federal
Reserve District, and on financial and economic topics.
Outsourcing Business Services and the Role of Central Administrative Offices
Yukako Ono

WP-02-01

Strategic Responses to Regulatory Threat in the Credit Card Market*
Victor Stango

WP-02-02

The Optimal Mix of Taxes on Money, Consumption and Income
Fiorella De Fiore and Pedro Teles

WP-02-03

Expectation Traps and Monetary Policy
Stefania Albanesi, V. V. Chari and Lawrence J. Christiano

WP-02-04

Monetary Policy in a Financial Crisis
Lawrence J. Christiano, Christopher Gust and Jorge Roldos

WP-02-05

Regulatory Incentives and Consolidation: The Case of Commercial Bank Mergers
and the Community Reinvestment Act
Raphael Bostic, Hamid Mehran, Anna Paulson and Marc Saidenberg

WP-02-06

Technological Progress and the Geographic Expansion of the Banking Industry
Allen N. Berger and Robert DeYoung

WP-02-07

Choosing the Right Parents: Changes in the Intergenerational Transmission
of Inequality  Between 1980 and the Early 1990s
David I. Levine and Bhashkar Mazumder

WP-02-08

The Immediacy Implications of Exchange Organization
James T. Moser

WP-02-09

Maternal Employment and Overweight Children
Patricia M. Anderson, Kristin F. Butcher and Phillip B. Levine

WP-02-10

The Costs and Benefits of Moral Suasion: Evidence from the Rescue of
Long-Term Capital Management
Craig Furfine

WP-02-11

On the Cyclical Behavior of Employment, Unemployment and Labor Force Participation
Marcelo Veracierto

WP-02-12

Do Safeguard Tariffs and Antidumping Duties Open or Close Technology Gaps?
Meredith A. Crowley

WP-02-13

Technology Shocks Matter
Jonas D. M. Fisher

WP-02-14

Money as a Mechanism in a Bewley Economy
Edward J. Green and Ruilin Zhou

WP-02-15

1

Working Paper Series (continued)
Optimal Fiscal and Monetary Policy: Equivalence Results
Isabel Correia, Juan Pablo Nicolini and Pedro Teles

WP-02-16

Real Exchange Rate Fluctuations and the Dynamics of Retail Trade Industries
on the U.S.-Canada Border
Jeffrey R. Campbell and Beverly Lapham

WP-02-17

Bank Procyclicality, Credit Crunches, and Asymmetric Monetary Policy Effects:
A Unifying Model
Robert R. Bliss and George G. Kaufman

WP-02-18

Location of Headquarter Growth During the 90s
Thomas H. Klier

WP-02-19

The Value of Banking Relationships During a Financial Crisis:
Evidence from Failures of Japanese Banks
Elijah Brewer III, Hesna Genay, William Curt Hunter and George G. Kaufman

WP-02-20

On the Distribution and Dynamics of Health Costs
Eric French and John Bailey Jones

WP-02-21

The Effects of Progressive Taxation on Labor Supply when Hours and Wages are
Jointly Determined
Daniel Aaronson and Eric French

WP-02-22

Inter-industry Contagion and the Competitive Effects of Financial Distress Announcements:
Evidence from Commercial Banks and Life Insurance Companies
Elijah Brewer III and William E. Jackson III

WP-02-23

State-Contingent Bank Regulation With Unobserved Action and
Unobserved Characteristics
David A. Marshall and Edward Simpson Prescott

WP-02-24

Local Market Consolidation and Bank Productive Efficiency
Douglas D. Evanoff and Evren Örs

WP-02-25

Life-Cycle Dynamics in Industrial Sectors. The Role of Banking Market Structure
Nicola Cetorelli

WP-02-26

Private School Location and Neighborhood Characteristics
Lisa Barrow

WP-02-27

Teachers and Student Achievement in the Chicago Public High Schools
Daniel Aaronson, Lisa Barrow and William Sander

WP-02-28

The Crime of 1873: Back to the Scene
François R. Velde

WP-02-29

Trade Structure, Industrial Structure, and International Business Cycles
Marianne Baxter and Michael A. Kouparitsas

WP-02-30

Estimating the Returns to Community College Schooling for Displaced Workers
Louis Jacobson, Robert LaLonde and Daniel G. Sullivan

WP-02-31

2

Working Paper Series (continued)
A Proposal for Efficiently Resolving Out-of-the-Money Swap Positions
at Large Insolvent Banks
George G. Kaufman

WP-03-01

Depositor Liquidity and Loss-Sharing in Bank Failure Resolutions
George G. Kaufman

WP-03-02

Subordinated Debt and Prompt Corrective Regulatory Action
Douglas D. Evanoff and Larry D. Wall

WP-03-03

When is Inter-Transaction Time Informative?
Craig Furfine

WP-03-04

Tenure Choice with Location Selection: The Case of Hispanic Neighborhoods
in Chicago
Maude Toussaint-Comeau and Sherrie L.W. Rhine

WP-03-05

Distinguishing Limited Commitment from Moral Hazard in Models of
Growth with Inequality*
Anna L. Paulson and Robert Townsend

WP-03-06

Resolving Large Complex Financial Organizations
Robert R. Bliss

WP-03-07

The Case of the Missing Productivity Growth:
Or, Does information technology explain why productivity accelerated in the United States
but not the United Kingdom?
Susanto Basu, John G. Fernald, Nicholas Oulton and Sylaja Srinivasan

WP-03-08

Inside-Outside Money Competition
Ramon Marimon, Juan Pablo Nicolini and Pedro Teles

WP-03-09

The Importance of Check-Cashing Businesses to the Unbanked: Racial/Ethnic Differences
William H. Greene, Sherrie L.W. Rhine and Maude Toussaint-Comeau

WP-03-10

A Firm’s First Year
Jaap H. Abbring and Jeffrey R. Campbell

WP-03-11

Market Size Matters
Jeffrey R. Campbell and Hugo A. Hopenhayn

WP-03-12

The Cost of Business Cycles under Endogenous Growth
Gadi Barlevy

WP-03-13

The Past, Present, and Probable Future for Community Banks
Robert DeYoung, William C. Hunter and Gregory F. Udell

WP-03-14

Measuring Productivity Growth in Asia: Do Market Imperfections Matter?
John Fernald and Brent Neiman

WP-03-15

Revised Estimates of Intergenerational Income Mobility in the United States
Bhashkar Mazumder

WP-03-16

3

Working Paper Series (continued)
Product Market Evidence on the Employment Effects of the Minimum Wage
Daniel Aaronson and Eric French

WP-03-17

Estimating Models of On-the-Job Search using Record Statistics
Gadi Barlevy

WP-03-18

Banking Market Conditions and Deposit Interest Rates
Richard J. Rosen

WP-03-19

Creating a National State Rainy Day Fund: A Modest Proposal to Improve Future
State Fiscal Performance
Richard Mattoon

WP-03-20

Managerial Incentive and Financial Contagion
Sujit Chakravorti, Anna Llyina and Subir Lall

WP-03-21

Women and the Phillips Curve: Do Women’s and Men’s Labor Market Outcomes
Differentially Affect Real Wage Growth and Inflation?
Katharine Anderson, Lisa Barrow and Kristin F. Butcher

WP-03-22

Evaluating the Calvo Model of Sticky Prices
Martin Eichenbaum and Jonas D.M. Fisher

WP-03-23

The Growing Importance of Family and Community: An Analysis of Changes in the
Sibling Correlation in Earnings
Bhashkar Mazumder and David I. Levine

WP-03-24

Should We Teach Old Dogs New Tricks? The Impact of Community College Retraining
on Older Displaced Workers
Louis Jacobson, Robert J. LaLonde and Daniel Sullivan

WP-03-25

Trade Deflection and Trade Depression
Chad P. Brown and Meredith A. Crowley

WP-03-26

China and Emerging Asia: Comrades or Competitors?
Alan G. Ahearne, John G. Fernald, Prakash Loungani and John W. Schindler

WP-03-27

International Business Cycles Under Fixed and Flexible Exchange Rate Regimes
Michael A. Kouparitsas

WP-03-28

Firing Costs and Business Cycle Fluctuations
Marcelo Veracierto

WP-03-29

Spatial Organization of Firms
Yukako Ono

WP-03-30

Government Equity and Money: John Law’s System in 1720 France
François R. Velde

WP-03-31

Deregulation and the Relationship Between Bank CEO
Compensation and Risk-Taking
Elijah Brewer III, William Curt Hunter and William E. Jackson III

WP-03-32

4

Working Paper Series (continued)
Compatibility and Pricing with Indirect Network Effects: Evidence from ATMs
Christopher R. Knittel and Victor Stango

WP-03-33

Self-Employment as an Alternative to Unemployment
Ellen R. Rissman

WP-03-34

Where the Headquarters are – Evidence from Large Public Companies 1990-2000
Tyler Diacon and Thomas H. Klier

WP-03-35

Standing Facilities and Interbank Borrowing: Evidence from the Federal Reserve’s
New Discount Window
Craig Furfine

WP-04-01

Netting, Financial Contracts, and Banks: The Economic Implications
William J. Bergman, Robert R. Bliss, Christian A. Johnson and George G. Kaufman

WP-04-02

Real Effects of Bank Competition
Nicola Cetorelli

WP-04-03

Finance as a Barrier To Entry: Bank Competition and Industry Structure in
Local U.S. Markets?
Nicola Cetorelli and Philip E. Strahan

WP-04-04

The Dynamics of Work and Debt
Jeffrey R. Campbell and Zvi Hercowitz

WP-04-05

Fiscal Policy in the Aftermath of 9/11
Jonas Fisher and Martin Eichenbaum

WP-04-06

Merger Momentum and Investor Sentiment: The Stock Market Reaction
To Merger Announcements
Richard J. Rosen

WP-04-07

Earnings Inequality and the Business Cycle
Gadi Barlevy and Daniel Tsiddon

WP-04-08

Platform Competition in Two-Sided Markets: The Case of Payment Networks
Sujit Chakravorti and Roberto Roson

WP-04-09

Nominal Debt as a Burden on Monetary Policy
Javier Díaz-Giménez, Giorgia Giovannetti, Ramon Marimon, and Pedro Teles

WP-04-10

On the Timing of Innovation in Stochastic Schumpeterian Growth Models
Gadi Barlevy

WP-04-11

Policy Externalities: How US Antidumping Affects Japanese Exports to the EU
Chad P. Bown and Meredith A. Crowley

WP-04-12

Sibling Similarities, Differences and Economic Inequality
Bhashkar Mazumder

WP-04-13

Determinants of Business Cycle Comovement: A Robust Analysis
Marianne Baxter and Michael A. Kouparitsas

WP-04-14

5

Working Paper Series (continued)
The Occupational Assimilation of Hispanics in the U.S.: Evidence from Panel Data
Maude Toussaint-Comeau

WP-04-15

Reading, Writing, and Raisinets1: Are School Finances Contributing to Children’s Obesity?
Patricia M. Anderson and Kristin F. Butcher

WP-04-16

Learning by Observing: Information Spillovers in the Execution and Valuation
of Commercial Bank M&As
Gayle DeLong and Robert DeYoung

WP-04-17

Prospects for Immigrant-Native Wealth Assimilation:
Evidence from Financial Market Participation
Una Okonkwo Osili and Anna Paulson

WP-04-18

Individuals and Institutions: Evidence from International Migrants in the U.S.
Una Okonkwo Osili and Anna Paulson

WP-04-19

Are Technology Improvements Contractionary?
Susanto Basu, John Fernald and Miles Kimball

WP-04-20

The Minimum Wage, Restaurant Prices and Labor Market Structure
Daniel Aaronson, Eric French and James MacDonald

WP-04-21

Betcha can’t acquire just one: merger programs and compensation
Richard J. Rosen

WP-04-22

Not Working: Demographic Changes, Policy Changes,
and the Distribution of Weeks (Not) Worked
Lisa Barrow and Kristin F. Butcher

WP-04-23

The Role of Collateralized Household Debt in Macroeconomic Stabilization
Jeffrey R. Campbell and Zvi Hercowitz

WP-04-24

Advertising and Pricing at Multiple-Output Firms: Evidence from U.S. Thrift Institutions
Robert DeYoung and Evren Örs

WP-04-25

Monetary Policy with State Contingent Interest Rates
Bernardino Adão, Isabel Correia and Pedro Teles

WP-04-26

Comparing location decisions of domestic and foreign auto supplier plants
Thomas Klier, Paul Ma and Daniel P. McMillen

WP-04-27

China’s export growth and US trade policy
Chad P. Bown and Meredith A. Crowley

WP-04-28

Where do manufacturing firms locate their Headquarters?
J. Vernon Henderson and Yukako Ono

WP-04-29

Monetary Policy with Single Instrument Feedback Rules
Bernardino Adão, Isabel Correia and Pedro Teles

WP-04-30

6

Working Paper Series (continued)
Firm-Specific Capital, Nominal Rigidities and the Business Cycle
David Altig, Lawrence J. Christiano, Martin Eichenbaum and Jesper Linde

WP-05-01

Do Returns to Schooling Differ by Race and Ethnicity?
Lisa Barrow and Cecilia Elena Rouse

WP-05-02

Derivatives and Systemic Risk: Netting, Collateral, and Closeout
Robert R. Bliss and George G. Kaufman

WP-05-03

Risk Overhang and Loan Portfolio Decisions
Robert DeYoung, Anne Gron and Andrew Winton

WP-05-04

Characterizations in a random record model with a non-identically distributed initial record
Gadi Barlevy and H. N. Nagaraja

WP-05-05

Price discovery in a market under stress: the U.S. Treasury market in fall 1998
Craig H. Furfine and Eli M. Remolona

WP-05-06

Politics and Efficiency of Separating Capital and Ordinary Government Budgets
Marco Bassetto with Thomas J. Sargent

WP-05-07

Rigid Prices: Evidence from U.S. Scanner Data
Jeffrey R. Campbell and Benjamin Eden

WP-05-08

Entrepreneurship, Frictions, and Wealth
Marco Cagetti and Mariacristina De Nardi

WP-05-09

Wealth inequality: data and models
Marco Cagetti and Mariacristina De Nardi

WP-05-10

What Determines Bilateral Trade Flows?
Marianne Baxter and Michael A. Kouparitsas

WP-05-11

7