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ESSAYS ON ISSUES

THE FEDERAL RESERVE BANK
OF CHICAGO

AUGUST 2011
NUMBER 289

Chicag­o Fed Letter
Why are manufacturers struggling to hire high-skilled workers?
by Britton Lombardi, senior associate economist, and William A. Testa, vice president and director of regional programs

The authors examine the apparent lack of high-skilled workers for the U.S. manufacturing
sector by focusing on the educational attainment and wage compensation of manufacturing
workers and their nonmanufacturing counterparts over the period 1990–2007.

The educational attainment
of the manufacturing
work force has been
converging with that of
the nonmanufacturing
work force.

U.S. manufacturers are often disappointed

Upskilling

with the supply of high-skilled workers
available to them, especially from the
pool of younger candidates. Manufacturers and their trade associations have
actively responded to this apparent shortage by heightening their recruitment
efforts, marketing the manufacturing
sector’s prospects, and improving their
skills certification and training programs.
If manufacturing employers are indeed
faced with an unduly short supply of
high-skilled workers, this is puzzling
given the falling levels and shares of
manufacturing employment in the U.S.
To further understand this reported
labor shortage, we look at trends in
“upskilling,” or improvements in average skill levels, of the overall U.S. work
force. We examine whether the manufacturing sector (compared with the
nonmanufacturing sector) has sought
and employed more high-skilled workers
versus low-skilled workers over time. In
addition, we analyze how wage premiums
in the manufacturing sector relative to
the nonmanufacturing sector have
changed over the past two decades.
Having to provide higher wage premiums
usually indicates tightening labor markets,
so we look at whether these premiums
for manufacturing labor have been ­
increasing in relative terms over time.
Finally, we touch on other challenges
that manufacturers may be facing in
hiring high-skilled workers.

In the U.S., manufacturing’s share of
payroll jobs has been contracting since
the middle of the twentieth century, with
accelerating declines over the past three
decades. A shrinking manufacturing
sector in the U.S. suggests that workers
would be readily available, since many
existing workers have been displaced
on account of plant closings and other
retrenchment decisions. However, what
may be true for the overall manufacturing
work force may be less true for highskilled segments of it. That is, both
technological change and heightened
global competition may be affecting
low-skilled manufacturing workers to a
greater extent. Meanwhile, the demand
for high-skilled workers has also been
tightening across the entire U.S. economy;
thus, manufacturing employers must
likely compete with nonmanufacturing
employers for these workers.
In recent decades, the U.S. work force
has been upskilling. As documented by
various researchers,1 upskilling across
the U.S. work force over the past century
is evidenced by rapid growth in educational attainment, particularly by the
increased numbers of high school and
college graduates. Researchers continue
to debate the reasons behind the continued broad-based upskilling in recent
decades. But a strong impetus for upskilling across the U.S. work force appears
to have arisen from employers’ growing

1. Share of work force, by educational attainment and industry
A. Less than high school diploma

B. High school diploma

percent
24

percent
39

20

35

6.9

6.6

16

31

12

27

3.5

8.1

23

8
1990

2000

1990

2007

2000

C. Some college

D. Bachelor’s degree or higher

percent
36

percent
35

32

30

28

2.5
3.5

2007

9.1

25
10.0

24

20

20
1990

2000

2007

15

1990

2000

2007

Nonmanufacturing

Manufacturing

Notes: The numbers between the manufacturing and nonmanufacturing work force series in each panel indicate their percentage
point differences. The data are for workers aged 25 and older.
Sources: Authors’ calculations based on data from the U.S. Census Bureau, 1990 Census of Population and Housing, Public
Use Microdata Samples, 1% sample; and 2000–07 American Community Survey.

2. Average hourly wages, by educational attainment and industry
			
1990
2000–07
Mfg Nonmfg Total

Mfg

% change from
1990 to 2000–07

Nonmfg Total

Mfg Nonmfg Total

Less than high school
diploma

15.25

13.77

14.25

14.85

14.16

14.31

–2.6

2.8

0.5

High school diploma

18.12

15.91

16.56

18.55

16.85

17.24

2.3

6.0

4.1

Some college

21.53

18.55

19.26

23.03

20.41

20.88

7.0

10.0

8.4

Bachelor’s degree

29.54

24.87

26.00

34.90

30.97

31.69

18.1

24.5

21.9

Master’s degree
or higher

37.08

32.27

33.41

46.66

43.21

43.86

25.8

33.9

31.3

Notes: Nominal average wages are deflated by the U.S. Bureau of Labor Statistics’ Consumer Price Index for All Urban Consumers (CPI-U)
to 2007 U.S. dollars. The data are for workers aged 25 and older. Mfg indicates manufacturing. Nonmfg indicates nonmanufacturing.
Sources: Authors’ calculations based on data from the U.S. Census Bureau, 1990 Census of Population and Housing, Public Use
Microdata Samples, 1% sample; and 2000–07 American Community Survey.

demand for high-skilled employees—
particularly for those who are facile with
technological advancements.2
To examine the educational attainment
of manufacturing workers, we draw on
the 1990 U.S. Census’s 1% Public Use
Microdata Sample (PUMS), as well as the

annual American Community Survey (ACS)
over the period 2000–07, both from the
U.S. Census Bureau. Educational attainment of workers correlates fairly well with
measured skill levels. Although some may
argue there are many manufacturing
skills that do not reflect formal education,
especially those involving on-the-job

training, we find that educational attainment correlates strongly with wages in
both manufacturing and nonmanufacturing sectors.3 Accordingly, as measured
by years of schooling completed, educational attainment and its changes over
time can serve as reasonable proxies for
skill levels and high-skilled-work-force
growth in manufacturing.
In general, manufacturing continues to
have a reputation for employing those
with lesser educational attainment. This
is confirmed by the 1% PUMS and ACS
data: Compared with the nonmanufacturing work force, the manufacturing
work force has greater shares of those
with only a high school diploma, as well
as those who have not completed high
school (see figure 1, panels A and B).
Nonetheless, the educational attainment
of the manufacturing work force has
been converging with that of the nonmanufacturing work force at both ends
of the educational attainment spectrum
over the past two decades. For the manufacturing work force, the share with less
than a high school diploma falls from
20.8% in 1990 to 12.9% in 2007; for the
nonmanufacturing work force, this share
drops from 13.9% in 1990 to 9.4% in
2007 (figure 1, panel A). Thus, it is clear
that this share for the manufacturing
sector falls much faster over this period.
For the manufacturing work force, the
share of those with a bachelor’s degree
or higher rises from 17.9% in 1990 to
25.0% in 2007; this share also goes up
from 27.9% to 34.1% over the same
period for the nonmanufacturing work
force (figure 1, panel D). Thus, the spread
between the college graduate share in
manufacturing and this share in the
nonmanufacturing sector drops from
10.0 percentage points to 9.1 percentage
points over the 1990–2007 period, indicating a convergence between the two
sectors’ work forces through upskilling.4  
Wage pressures

Beyond the increasing broad demand
for high-skilled workers across the manufacturing and nonmanufacturing sectors
alike, is there further evidence to suggest
that manufacturing employers strain to
acquire such workers? In the economics
literature, manufacturing has been shown
to consistently offer a wage premium

3. Manufacturing wage premiums, by educational attainment
1990
		
Premium
(dollars)

2000

% of 		
nonmfg
Premium
wage
(dollars)

2007

% of		
nonmfg
Premium
wage
(dollars)

% of
nonmfg
wage

Less than high school diploma

1.11*

8.09

–0.10*

–0.66

0.29*

2.11

High school diploma

1.21*

7.59

1.22*

7.24

0.55*

3.32

Some college

1.42*

7.63

1.22*

5.98

0.67*

3.32

Bachelor’s degree

2.70*

10.86

1.71*

5.51

1.45*

4.69

Master’s degree or higher

2.25*

6.96

–1.24*

–2.83

–0.92*

–2.06

*Significant at the 1% level.
Notes: All wage premiums are in 2007 U.S. dollars. Wage premiums are measured by the manufacturing employment regression
coefficients for each of the educational attainment levels. Regressions also control for gender, experience, and U.S. Bureau of
Economic Analysis (BEA) region. For information on BEA regions, see www.bea.gov/regional/docs/regions.cfm. The data are for
workers aged 25 and older. Nonmfg indicates nonmanufacturing.
Sources: Authors’ calculations based on data from the U.S. Census Bureau, 1990 Census of Population and Housing, Public Use
Microdata Samples, 1% sample; and 2000–07 American Community Survey.

(relative to the nonmanufacturing sector). However, such wage premiums do
not necessarily imply tight labor markets.
Previous studies have explained the manufacturing wage premium as being (alternatively) a byproduct of unionization;
compensation for less desirable working
conditions; and “efficiency wages,” or
overcompensation to workers to ensure
they will not shirk their responsibilities.
Given that wage premiums have been
historically typical of the manufacturing
sector, somewhat stronger evidence may
be needed to indicate tightening labor
markets over time.
Actually, aggregate evidence of late has
shown a countertrend or at least an easing
of the wage premium in U.S. manufacturing. Over the past two decades, manufacturing wages have been rising less
rapidly in the U.S. work force: From 1990
through 2007, average annual hourly
wage increases (net of overtime) in the
private nonmanufacturing sector have
cumulatively outpaced those in manufacturing by amounts ranging from 5%
(e.g., retail and wholesale trade and other
services) to 23% (e.g., finance, insurance,
and real estate).5
We focus on changing wage differences
between the manufacturing and nonmanufacturing sectors in figure 2. To
account for different skill levels, we compare the average hourly wages of the
manufacturing and nonmanufacturing
sectors for individual workers categorized
by their educational attainment. The
average hourly wage for manufacturing
workers at all education levels is higher

than that for nonmanufacturing workers
in both periods we consider. In 1990, the
largest wage gap between manufacturing
workers and nonmanufacturing workers
was for individuals with a master’s degree
or higher, with this difference equaling
almost $5 per hour. In 2000–07, individuals with only a bachelor’s degree had
the largest gap: Manufacturing workers
earned about $4 more an hour than
their nonmanufacturing counterparts.
In each educational attainment category,
the wage spread converged from 1990
to 2000–07, with the wages of the nonmanufacturing sector outpacing those
of the manufacturing sector. Manufacturing workers having less than a high
school diploma experienced actual real
wage declines from 1990 to 2000–07,
while nonmanufacturing workers with
the same level of educational attainment
eked out small gains. In higher educational attainment categories, average
wages grew in both sectors, though nonmanufacturing wages rose more rapidly.
Nonmanufacturing workers with some
college saw wage gains of 10%, versus
gains of 7% for their manufacturing
counterparts. Among those with only
bachelor’s degrees, nonmanufacturing
wages jumped 24.5%, compared with
18.1% for manufacturing wages.
To further examine wage premiums paid
by manufacturing employers with more
statistical controls, we run ordinary least
squares regressions on observations of
individual workers in the manufacturing
and nonmanufacturing sectors, with
hourly wage6 as our dependent variable.

In doing so, we account for each worker’s
human capital—both education and experience—along with gender and geography of the workplace. To proxy for
worker skill level, we segment our observations of all private sector workers into
five mutually exclusive categories of educational attainment: 1) less than a high
school diploma, 2) a high school diploma,
3) some college, 4) a bachelor’s degree,
and 5) a master’s degree or higher. We
run separate regressions for each year
(1990, 2000, and 2007) and education
level, and distinguish manufacturing workers from nonmanufacturing workers.
In figure 3, we report the manufacturing
wage premium as the dollar amount per
hour, as well as its percentage of the
average hourly wage for nonmanufacturing workers having the same level of
education. With a few exceptions, we find
that the estimated wage effect of being
in the manufacturing sector is positive
and statistically significant.7 In 1990, this
wage effect is worth between 6.96% and
10.86% of the average wage of nonmanufacturing workers. By 2007, the wage
effect reduced to being worth between
–2.06% and 4.69% of the nonmanufacturing sector’s average wage. Manufacturing wage premiums for workers with
Charles L. Evans, President ; Daniel G. Sullivan,
Executive Vice President and Director of Research;
Spencer Krane, Senior Vice President and Economic
Advisor ; David Marshall, Senior Vice President, financial
markets group ; Daniel Aaronson, Vice President,
microeconomic policy research; Jonas D. M. Fisher,
Vice President, macroeconomic policy research; Richard
Heckinger, Assistant Vice President, markets team;
Anna L. Paulson, Vice President, finance team; William A.
Testa, Vice President, regional programs, and Economics
Editor ; Helen O’D. Koshy and Han Y. Choi, Editors  ;
Rita Molloy and Julia Baker, Production Editors ;
Sheila A. Mangler, Editorial Assistant.
Chicago Fed Letter is published by the Economic
Research Department of the Federal Reserve Bank
of Chicago. The views expressed are the authors’
and do not necessarily reflect the views of the
Federal Reserve Bank of Chicago or the Federal
Reserve System.
© 2011 Federal Reserve Bank of Chicago ­
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ISSN 0895-0164

some college or a bachelor’s degree generally remain superior to those of others.
Most importantly, contrary to what we
might expect to find if the manufacturing labor markets were tightening, the
manufacturing wage premium has tended
to decline over time for workers of nearly
all educational attainment levels.  
Other factors making hiring challenging

We find a persistent, albeit declining,
wage premium for U.S. manufacturing
workers. Given this finding, how might
we understand the apparent tightness in
U.S. manufacturing labor markets, particularly for high-skilled workers? For one,
U.S. manufacturers face extraordinary
competition for high-skilled labor from
offshore manufacturing employers, as
well as domestic nonmanufacturing
employers. In addition, manufacturing
firms may face a number of challenges

in recruiting talent from the pool of available workers, which the feasible wage
premium may not be able to overcome.  
Prospective workers may be discounting
employment opportunities in the U.S.
manufacturing sector, since they perceive
it as being in decline, with its employees
all too often being subject to temporary
job interruptions, underemployment, and
layoffs. Also, as the numbers of potential
manufacturing employees are falling,
the costs of offering traditional or legacy
training programs are rising for manufacturing firms. When manufacturing
job numbers were very high, local schools,
unions, and employers could more easily
gather a sufficient number of students
to make the scale of their training operations affordable.8 With the waning of
such training programs, manufacturing
is losing another valuable avenue for
its firms to acquire new workers.

1 See, e.g., Daniel Aaronson and Daniel

hourly wages and educational attainment
for manufacturing and nonmanufacturing
workers is 0.40 and 0.33, respectively, over
the period 2000–07.

Sullivan, 2002, “Growth in worker quality,”
Chicago Fed Letter, Federal Reserve Bank of
Chicago, No. 174, February.

2 See, e.g., David H. Autor, 2009, “Explain-

ing trends in wages, work, and occupations,”
Chicago Fed Letter, Federal Reserve Bank of
Chicago, No. 261, April; and David H. Autor,
Frank Levy, and Richard J. Murnane, 2002,
“Upstairs, downstairs: Computers and skills
on two floors of a large bank,” Industrial
and Labor Relations Review, Vol. 55, No. 3,
April, pp. 432–447.

3 According to our calculations based on
ACS data, the correlation between real

4

For both manufacturing and nonmanufacturing sectors, we also look at their shares
of those with only a high school diploma
and those with some college (figure 1,
panels B and C), but all these shares stay
relatively flat over the 1990–2007 period.

5

Federal Reserve Bank of Dallas, 2008,
Opportunity Knocks: Selling Our Services to the
World—2007 Annual Report, exhibit 9, top
panel, p. 24, available at www.dallasfed.org/
fed/annual/2007/ar07.pdf.

Conclusion

According to our analysis, continued
manufacturing wage premiums do not
adequately explain the apparent labor
tightness that manufacturers have experienced. Wage premiums actually
shrunk from the early 1990s to the late
2000s, even for those workers with higher
educational attainment. One possibility
is that declining manufacturing job prospects may be self-reinforcing, leading
to a negative image among prospective
employees. If so, the pool of available
workers at any given educational attainment may be inferior to that in previous
times. Accordingly, U.S. manufacturers
may need to increase their efforts in marketing their prospects and improving
their skills certification and training programs to gain more qualified candidates.

6

This is generated by dividing deflated annual
income by (weeks worked times usual hours
worked per week).

7

In order to further refine skill differences,
we isolate wages and experience of workers
in specific occupations over the period
2000–07. On average, over all occupations,
we find that the manufacturing sector
paid a wage premium of $0.68 per hour,
almost 2.78% of the average hourly nonmanufacturing wage.

8

There are some ongoing initiatives that
attempt to address this problem. See, ­
e.g., http://institute.nam.org/page/edu_ ­
workforce_skills_cert.