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FRBSF Economic Letter
2017-31 | October 23, 2017 | Research from Federal Reserve Bank of San Francisco

Missing Growth from Creative Destruction
Pete Klenow and Huiyu Li
When products disappear from the market with no substitutes from the same manufacturer,
they may have been replaced by cheaper or better products from a different manufacturer.
Official measurements typically approximate price changes from such creative destruction
using price changes for products that were not replaced. This can lead to overstating inflation
and, in turn, understating economic growth. A recent estimate suggests that around 0.6
percentage point of growth is missed per year. The bias has not increased over time, however,
so it does not explain the slowdown in productivity growth.

A gloomy view of the economy suggests that the measured slowdown in U.S. productivity growth since 2004
reflects a true slowdown in innovation and productivity gains. From 1995 to 2004 businesses boosted the
average growth rate to nearly 3.75 percentage points annually by adopting information technology (IT) to
make their operations more efficient (Byrne, Fernald, and Reinsdorf 2017). Since then, measured
productivity growth has slowed to around 1.75 percentage points per year. Perhaps it has become more
difficult to achieve the same rapid rate of improvement as in the past. But has productivity growth truly
slowed down?
To answer this question, one needs to keep in mind that measured productivity growth is designed to capture
growth in market activities. Thus, it may not fully capture the growth in people’s economic welfare because it
misses out on important dimensions such as increasing lifespans and rising home production. So, even if the
measurement is correct, a slowdown in measured productivity growth does not necessarily reflect a
slowdown in welfare growth. For example, many recent IT innovations involve nonmarket activities such as
time spent on social media and time saved from shopping online. Although these areas may improve welfare,
they have not historically been covered by productivity measurements, so ignoring them cannot directly
contribute to any growing understatement of market-sector growth.
This Economic Letter focuses on measuring growth from innovation in parts of the economy that have
traditionally been within the scope of productivity measurement. Past research has found that measurement
problems in the IT sector associated with market production and offshoring activities cannot explain much of
the growth slowdown (see Aghion et al. 2017 for references). In this Letter, we consider whether errors in
measuring innovation outside the IT sector can explain the substantial slowdown.

Quality adjustment in inflation measurement
As a first step toward measuring growth, the Bureau of Economic Analysis adds up the dollar value of goods
and services sold, which equals “nominal output.” However, due to inflation—a general increase in overall
price levels—one dollar today does not have the same purchasing power as one dollar three decades ago. This

FRBSF Economic Letter 2017-31

October 23, 2017

means the agencies measuring these data need to subtract the inflation rate from growth in nominal output
to arrive at growth in real output. Hence, a 1% overstatement of inflation translates into a 1% understatement
of measured real output growth. This translates into a 1% understatement of productivity growth as well,
because productivity growth is the difference between real output growth and the growth in capital and labor
inputs used in production.
The natural follow-up question then is, how is inflation measured? Inflation is meant to capture the change
in the purchasing power of a dollar. Suppose between 2016 and 2017 the price for the exact same car
increases by 3%. Then the inflation rate for that car is obviously 3%. However, car producers typically update
features of their models from one year to the next. So a 2017 model may have better fuel efficiency than the
2016 model. In this event, the true inflation rate is lower than the 3% change in nominal price because the
quality of the car has improved. The measurement agencies need to take this quality improvement out of the
3% to arrive at what is called a “quality-adjusted price change.” Inflation for the car is mismeasured if too
much or too little quality adjustment is taken out of nominal price changes by the Bureau of Labor Statistics
(BLS), which calculates inflation rates in the United States.
Bias from missing out on quality improvements by the same producer was one source of potential
mismeasurement emphasized by the famous Boskin Commission (1996). The Boskin Commission was a
committee appointed by the U.S. Senate to assess the reliability of inflation data. In addition to bias from
understating quality improvements, the Commission pointed out biases from not capturing the benefits of
new product varieties and from not properly accounting for how consumers switch to cheaper substitutes
when the price of a product increases.
Products such as electronics and apparel are particularly affected because their quality changes frequently.
The BLS uses several methods to adjust for these changes. These methods, and the Boskin Commission’s
critique of them, focus on updates made by existing producers, or “incumbents,” to their own products. But
what happens when a producer is replaced by a different producer—for example, when a new restaurant
forces a nearby restaurant out of business because customers prefer their menu?
When a product disappears without being replaced by a new version from the same producer in the same
location, the BLS typically fills in or “imputes” the missing price and then starts tracking a new item. In
particular, the BLS imputes inflation for the disappearing item to be the same as inflation for similar
products that remain on the market. The BLS resorts to such imputation roughly twice as often as it directly
estimates quality changes (Aghion et al. 2017).

Missing growth due to imputation
In doing such imputation, the BLS assumes the inflation rate is the same for changeovers from old to new
producers as it is for all surviving items. This may not be an accurate assumption of the true values. Research
since Schumpeter (1942) highlights growth driven by so-called creative destruction. Under creative
destruction, new producers replace existing producers precisely because they introduce a product with a
lower quality-adjusted price. The items that survive are those that do not experience creative destruction.
Most of these surviving items have not been updated at all, according to the BLS. Hence, by using the
inflation of surviving products to approximate the inflation rate of products that disappear, the BLS could be
overstating the inflation rate of the disappearing products.
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October 23, 2017

To quantify the extent of missing growth caused by imputation bias, in Aghion et al. (2017), we and our
colleagues analyze the market share of incumbent producers—that is, the sales of incumbents relative to total
sales. When two products have the same quality, the producer who sells at a lower price will sell more and
hence have a higher market share. More specifically, a product whose price relative to its quality—qualityadjusted price—is lower will have a higher market share. By this logic, the market share of incumbent
products shrinks when their quality-adjusted prices increase relative to products made by new market
entrants. Imputation assumes that these inflation rates are the same, so that incumbent market shares
should be stable. If instead incumbent market shares tend to shrink over time, then this would be a sign that
imputation overstates the inflation rate for creatively destroyed products, leading to an understatement of
growth. The more incumbent market shares shrink, the larger the bias.
Figure 1 displays our estimates of missing growth due to imputation, based on the employment shares of
incumbent establishments in the U.S. Census (Aghion et al. 2017). An establishment is a given site, such as a
Wal-Mart outlet or a GM auto factory. Ideally, one would want to measure an establishment’s market share
using sales data. Unfortunately, sales data are not available for all establishments in the economy. However,
since producers need to increase inputs to sell more, they tend to use more inputs when their market share
rises. We therefore use employment and payroll shares to proxy for the sales share. Figure 1 also shows the
true growth calculated by adding this source of missing growth to BLS measured productivity growth. For
measured growth, we use BLS multifactor productivity in labor-augmenting units including the contribution
of research and development.
There are two key takeaways from Figure
1. First, we estimate missing growth to be
about 0.6% per year on average from
1983 to 2013. By this estimate, roughly
one-fourth of true growth is missed.
Second, while there are fluctuations, no
clear trends emerge for missing growth.
In particular, missing growth has not
systematically increased over time, as
reflected in the true growth series. There
is a substantial decline in productivity
growth post-2004 even after adjusting
for missing growth.

Figure 1
Missing growth and true growth
Percent
3.5
3

True growth,
5-year average

2.5
2
1.5
1
0.5

Missing growth,
5-year average

Our approach in Aghion et al. (2017) can
0
drill down to find missing growth in
1985
1990
1995
2000
2005
2010
2015
individual sectors. Figure 2 displays the
Note: True growth is the sum of missing growth and BLS multifactor
three sectors that contributed the most to
productivity series in labor-augmenting units.
missing growth: retailers, restaurants
and hotels, and health care. Each of these contributes about one-sixth of total missing growth. In contrast,
there was little missing growth in manufacturing, which has been the focus of so much attention. Over our
sample period, we tend to find more missing growth in sectors with higher rates of entry of new
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FRBSF Economic Letter 2017-31

establishments. For retail, our missing
growth could reflect unmeasured
productivity gains brought by new
outlets—so-called outlet-bias. Our
numbers suggest that outlet bias may be
much larger than previous estimates
from the Boskin Commission.

October 23, 2017

Figure 2
Contributions to missing growth by selected sectors
Percent
18
16
14
12

Conclusion

10

This Letter considers whether inflation is
8
overstated when items disappear and are
6
replaced by cheaper or better items. If so,
4
official government statistics could be
2
missing some growth. If this problem
0
had gotten worse over time, it could help
Retail trade
Restaurants & hotels
Health care
Manufacturing
explain the slowdown in measured
productivity growth since 2004.
However, we find that missing growth has been relatively constant over time, so true productivity growth has
slowed, even after accounting for this bias. Although the bias does not explain much of the sharp decline in
productivity growth, its magnitude is economically significant—nearly 0.6% per year on average, or about
one-fourth of true growth.
Measuring real growth properly is useful for addressing a host of questions. For example, existing studies use
measured inflation to calculate the real income of children relative to their parents. Chetty et al. (2017) find
that 50% of children born in 1984 achieved higher incomes than their parents at age 30. Adjusting for
missing growth would raise the real income of children about 17% relative to their parents, increasing the
fraction of those who do better than their parents by a meaningful amount. Thus, to the extent that inflation
is overstated due to imputed values, a larger fraction of children appear to be better off economically than
their parents. This improvement in economic welfare can shine a bit more positive light on current
conditions, despite the gloom of slower productivity growth.
Pete Klenow is a professor of economics at Stanford University and a visiting scholar in the Economic
Research Department of the Federal Reserve Bank of San Francisco.
Huiyu Li is an economist in the Economic Research Department of the Federal Reserve Bank of San
Francisco.

References
Aghion, Philippe, Antonin Bergeaud, Timo Boppart, Peter J. Klenow, and Huiyu Li. 2017. “Missing Growth from Creative
Destruction.” FRBSF San Francisco Working Paper 2017-04. http://www.frbsf.org/economicresearch/publications/working-papers/2017/04/
Boskin, Michael, Robert J. Gordon, Ellen Dullberger, Zvi Grilliches, and Dale Jorgenson. 1996. “Toward a More Accurate
Measure of the Cost of Living.” Final report of the Senate Finance Committee from the Advisory Commission to
Study the Consumer Price Index.

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FRBSF Economic Letter 2017-31

October 23, 2017

Byrne, David, John G. Fernald, and Marshall Reinsdorf. 2017. “Does Growing Mismeasurement Explain Disappointing
Growth?” FRBSF Economic Letter 2017-04 (February 13), Figure 1. http://www.frbsf.org/economicresearch/publications/economic-letter/2017/february/does-growing-mismeasurement-explain-disappointingproductivity/
Chetty, Raj, David Grusky, Maximilian Hell, Nathaniel Hendren, Robert Manduca, and Jimmy Narang. 2017. “The
Fading American Dream: Trends in Absolute Income Mobility since 1940.” Science.
http://science.sciencemag.org/content/sci/early/2017/04/21/science.aal4617.full.pdf
Schumpeter, Joseph. 1942. Capitalism, Socialism, and Democracy. New York: Harper & Bros.

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