This paper studies firm diversification over 6-digit NAICS industries in U.S. manufacturing. We find that firms specializing in fewer industries now account for a substantially greater share of production than 40 years ago. This reallocation is a key driver of rising industry concentration. Specialized firms have displaced diversified firms among industry leaders'absent this reallocation concentration would have decreased. We then provide evidence that specialized firms produce higher-quality goods: specialized firms tend to charge higher unit prices and are more insulated against Chinese import competition. Based on our empirical findings, we propose a theory in which growth shifts demand toward specialized, high-quality firms, which eventually increases concentration. We conclude that one should expect rising industry concentration in a growing economy.
-
Growth is Getting Harder to Find, Not Ideas
April 2025
Working Paper Number:
CES-25-21
Relatively flat US output growth versus rising numbers of US researchers is often interpreted as evidence that "ideas are getting harder to find." We build a new 46-year panel tracking the universe of U.S. firms' patenting to investigate the micro underpinnings of this claim, separately examining the relationships between research inputs and ideas (patents) versus ideas and growth. Over our sample period, we find that researchers' patenting productivity is increasing, there is little evidence of any secular decline in high-quality patenting common to all firms, and the link between patents and growth is present, differs by type of idea, and is fairly stable. On the other hand, we find strong evidence of secular decreases in output unrelated to patenting, suggesting an important role for other factors. Together, these results invite renewed empirical and theoretical attention to the impact of ideas on growth. To that end, our patent-firm bridge, which will be available to researchers with approved access, is used to produce new, public-use statistics on the Business Dynamics of Patenting Firms (BDS-PF).
View Full
Paper PDF
-
IMPORTING, EXPORTING AND FIRM-LEVEL EMPLOYMENT VOLATILITY
June 2013
Working Paper Number:
CES-13-31
In this paper, we use detailed trade and transactions data for the U.S. manufacturing sector to empirically analyze the direction and magnitude of the association between firm-level exposure to trade and the volatility of employment growth. We find that, relative to purely domestic firms, firms that only export and firms that both export and import are less volatile, whereas firms that only import are more volatile. The positive relationship between importing and volatility is driven mainly by firms that switch in and out of importing. We also document a significant degree of heterogeneity across trading firms in terms of the duration of time and intensity with which firms trade, the number and type of products they trade and the number and characteristics of their trading partners. We find these factors to play an important role in explaining the differential impact of trading on employment volatility experienced by these firms.
View Full
Paper PDF
-
Import Competition from and Offshoring to Low-Income Countries: Implications for Employment and Wages at U.S. Domestic Manufacturers
January 2017
Working Paper Number:
CES-17-31
Using confidential linked firm-level trade transactions and census data between 1997 and 2012, we provide new evidence on how American firms without foreign affiliates adjust employment and wages as they adapt to import competition from low-income countries. We provide stylized facts on the input sourcing strategies of these domestic firms, contrasting them with multinationals operating in the same industry. We then investigate how changes in firm input purchases from low-income countries as well as domestic market import penetration from these sources are correlated with changes in employment and wages at surviving domestic firms. Greater offshoring by domestic firms from low-income countries correlates with larger declines in manufacturing employment and in the average production workers' wage. Given the negative association, however, the estimated magnitudes are small, even for a narrow measure of offshoring that includes only intermediate goods. Import penetration of U.S. markets from these sources is associated with relatively larger changes in employment for arm's length importing firms, but has no significant correlation with employment changes at firms that do not trade. Given differences in the degree of both offshoring and import penetration, we find substantial variation across industries in the magnitude of changes associated with low-income country imports.
View Full
Paper PDF
-
Rising Markups or Changing Technology?
September 2022
Working Paper Number:
CES-22-38R
Recent evidence suggests the U.S. business environment is changing, with rising market concentration and markups. The most prominent and extensive evidence backs out firm-level markups from the first-order conditions for variable factors. The markup is identified as the ratio of the variable factor's output elasticity to its cost share of revenue. Our analysis starts from this indirect approach, but we exploit a long panel of manufacturing establishments to permit output elasticities to vary to a much greater extent - relative to the existing literature - across establishments within the same industry over time. With our more detailed estimates of output elasticities, the measured increase in markups is substantially dampened, if not eliminated, for U.S. manufacturing. As supporting evidence, we relate differences in the markups' patterns to observable changes in technology (e.g., computer investment per worker, capital intensity, diversification to non-manufacturing) and find patterns in support of changing technology as the driver of those differences.
View Full
Paper PDF
-
Volatility and Dispersion in Business Growth Rates: Publicly Traded Versus Privately Held Firms
July 2006
Working Paper Number:
CES-06-17
We study the variability of business growth rates in the U.S. private sector from 1976 onwards. To carry out our study, we exploit the recently developed Longitudinal Business Database (LBD), which contains annual observations on employment and payroll for all U.S. businesses. Our central finding is a large secular decline in the cross sectional dispersion of firm growth rates and in the average magnitude of firm level volatility. Measured the same way as in other recent research, the employment-weighted mean volatility of firm growth rates has declined by more than 40% since 1982. This result stands in sharp contrast to previous findings of rising volatility for publicly traded firms in COMPUSTAT data. We confirm the rise in volatility among publicly traded firms using the LBD, but we show that its impact is overwhelmed by declining volatility among privately held firms. This pattern holds in every major industry group. Employment shifts toward older businesses account for 27 percent or more of the volatility decline among privately held firms. Simple cohort effects that capture higher volatility among more recently listed firms account for most of the volatility rise among publicly traded firms.
View Full
Paper PDF
-
Competition, Firm Innovation, and Growth under Imperfect Technology Spillovers
July 2024
Working Paper Number:
CES-24-40
We study how friction in learning others' technology, termed 'imperfect technology spillovers,' incentivizes firms to use different types of innovation and impacts the implications of competition through changes in innovation composition. We build an endogenous growth model in which multi-product firms enhance their products via internal innovation and enter new product markets through external innovation. When learning others' technology takes time due to this friction, increased competitive pressure leads firms with technological advantages to intensify internal innovation to protect their markets, thereby reducing others' external innovation. Using the U.S. administrative firm-level data, we provide regression results supporting the model predictions. Our findings highlight the importance of strategic firm innovation choices and changes in their composition in shaping the aggregate implications of competition.
View Full
Paper PDF
-
The Rising Returns to R&D: Ideas Are Not Getting Harder to Find
May 2025
Working Paper Number:
CES-25-29
R&D investment has grown robustly, yet aggregate productivity growth has stagnated. Is this because 'ideas are getting harder to find'? This paper uses micro-data from the US Census Bureau to explore the relationship between R&D and productivity in the manufacturing sector from 1976 to 2018. We find that both the elasticity of output (TFP) with respect to R&D and the marginal returns to R&D have risen sharply. Exploring factors affecting returns, we conclude that R&D obsolescence rates must have risen. Using a novel estimation approach, we find consistent evidence of sharply rising technological rivalry. These findings suggest that R&D has become more effective at finding productivity-enhancing ideas but these ideas may also render rivals' technologies obsolete, making innovations more transient.
View Full
Paper PDF
-
U.S. Market Concentration and Import Competition
August 2022
Working Paper Number:
CES-22-34
Many studies have documented that market concentration has risen among U.S. firms in recent decades. In this paper, we show that this rise in concentration was accompanied by tougher product market competition due to the entry of foreign competitors. Using confidential census data covering the universe of all firm sales in the U.S. manufacturing sector, we find that rising import competition increased concentration among U.S. firms by reallocating sales from smaller to larger U.S. firms and by causing firm exit. However, this increase in concentration was counteracted by the expansion of foreign firms, which reduced domestic firms' share of the U.S. market inclusive of foreign firms' sales. We find that once the sales of foreign exporters are taken into account, U.S. marketconcentration in manufacturing was stable between 1992 and 2012.
View Full
Paper PDF
-
R&D or R vs. D?
Firm Innovation Strategy and Equity Ownership
April 2020
Working Paper Number:
CES-20-14
We analyze a unique dataset that separately reports research and development expenditures
for a large panel of public and private firms. Definitions of 'research' and 'development' in this dataset, respectively, correspond to definitions of knowledge 'exploration' and 'exploitation' in the innovation theory literature. We can thus test theories of how equity ownership status relates to innovation strategy. We find that public firms have greater research intensity than private firms, inconsistent with theories asserting private ownership is more conducive to exploration. We also find public firms invest more intensely in innovation of all sorts. These results suggest relaxed financing constraints enjoyed by public firms, as well as their diversified shareholder bases, make them more conducive to investing in all types of innovation. Reconciling several seemingly conflicting results in prior research, we find private-equity-owned firms, though not less innovative overall than other private firms, skew their innovation strategies toward development and away from research.
View Full
Paper PDF
-
The Role of R&D Factors in Economic Growth
November 2024
Working Paper Number:
CES-24-69
This paper studies factor usage in the R&D sector. I show that the usage of non-labor inputs in R&D is significant, and that their usage has grown much more rapidly than the R&D workforce. Using a standard growth decomposition applied to the aggregate idea production function, I estimate that at least 77% of idea growth since the early 1960s can be attributed to the growth of non-labor inputs in R&D. I demonstrate that a similar pattern would hold on the balanced growth path of a standard semi-endogenous growth model, and thus that the decomposition is not simply a by-product of rising research intensity. I then show that combining long-running differences in factor growth rates with non-unitary elasticities of substitution in idea production leads to a slowdown in idea growth whenever labor and capital are complementary. I conclude by estimating this elasticity of substitution and demonstrate that the results favor complimentarities.
View Full
Paper PDF