Wages for the vast majority of workers have stagnated since the 1980s while productivity
has grown. We investigate two coexisting explanations based on rising market power: 1. Monopsony, where dominant firms exploit the limited mobility of their own workers to pay lower wages; and 2. Monopoly, where dominant firms charge too high prices for what they sell, which lowers production and the demand for labor, and hence equilibrium wages economy-wide. Using establishment data from the US Census Bureau between 1997 and 2016, we find evidence of both monopoly and monopsony, where the former is rising over this period and the latter is stable. Both contribute to the decoupling of productivity and wage growth, with monopoly being the primary determinant: in 2016 monopoly accounts for 75% of wage stagnation, monopsony for 25%.
-
Market Power And Wage Inequality
September 2022
Working Paper Number:
CES-22-37
We propose a theory of how market power affects wage inequality. We ask how goods and labor market power jointly affect the level of wages, the Skill Premium, and wage inequality. We then use detailed microdata from the US Census between 1997 and 2016 to estimate the parameters of labor supply, technology and the market structure. We find that a less competitive market structure lowers the wage level, contributes 7% to the rise in the Skill Premium and accounts for half of the increase in between-establishment wage variance.
View Full
Paper PDF
-
The Adoption of Non-Rival Inputs and Firm Scope
April 2026
Working Paper Number:
CES-26-28
Custom software is distinct from other types of capital in that it is non-rival'once a firm makes an investment in custom software, it can be used simultaneously across its many establishments. Using confidential U.S. Census data, we document that while firms with more establishments are more likely to invest in custom software, they spend less on it as a share of total capital expenditure. We explain these empirical patterns by developing a model that incorporates the non-rivalry of custom software. In the model, firms choose whether to adopt custom software, the intensity of their investment, and their scope, balancing the cost of managing multiple establishments with the increasing returns to scope from the nonrivalrous custom software investment. Using the calibrated model, we assess the extent to which the decline in the rental rate of custom software over the past 40 years can account for a number of macroeconomic trends, including increases in firm scope and concentration.
View Full
Paper PDF
-
Entry, Exit, and the Determinants of Market Structure
September 2009
Working Paper Number:
CES-09-23
Market structure is determined by the entry and exit decisions of individual producers. These decisions are driven by expectations of future profits which, in turn, depend on the nature of competition within the market. In this paper we estimate a dynamic, structural model of entry and exit in an oligopolistic industry and use it to quantify the determinants of market structure and long-run firm values for two U.S. service industries, dentists and chiropractors. We find that entry costs faced by potential entrants, fixed costs faced by incumbent producers, and the toughness of short-run price competition are all important determinants of long run firm values and market structure. As the number of firms in the market increases, the value of continuing in the market and the value of entering the market both decline, the probability of exit rises, and the probability of entry declines. The magnitude of these effects differ substantially across markets due to differences in exogenous cost and demand factors and across the dentist and chiropractor industries. Simulations using the estimated model for the dentist industry show that pressure from both potential entrants and incumbent firms discipline long-run profits. We calculate that a seven percent reduction in the mean sunk entry cost would reduce a monopolist's long-run profits by the same amount as if the firm operated in a duopoly.
View Full
Paper PDF
-
The Evolution of U.S. Retail Concentration
March 2022
Working Paper Number:
CES-22-07
Increases in national concentration have been a salient feature of industry dynamics in the U.S. and have contributed to concerns about increasing market power. Yet, local trends may be more informative about market power, particularly in the retail sector where consumers have traditionally shopped at nearby stores. We find that local concentration has increased almost in parallel with national concentration using novel Census data on product-level revenue for all U.S. retail stores. The increases in concentration are broad based, affecting most markets, products, and retail industries. We implement a new decomposition of the national Herfindahl Hirschman Index and show that despite similar trends, national and local concentration reflect different changes in the retail sector. The increase in national concentration comes from consumers in different markets increasingly buying from the same firms and does not reflect changes in local market power. We estimate a model of retail competition which links local concentration to markups. The model implies that the increase in local concentration explains one-third of the observed increase in markups.
View Full
Paper PDF
-
Local and National Concentration Trends in Jobs and Sales: The Role of Structural Transformation
November 2023
Working Paper Number:
CES-23-59
National U.S. industrial concentration rose between 1992-2017. Simultaneously, the Herfindhahl Index of local (six-digit-NAICS by county) employment concentration fell. This divergence between national and local employment concentration is due to structural transformation. Both sales and employment concentration rose within industry-by-county cells. But activity shifted from concentrated Manufacturing towards relatively un-concentrated Services. A stronger between-sector shift in employment relative to sales explains the fall in local employment concentration. Had sectoral employment shares remained at their 1992 levels, average local employment concentration would have risen by 9% by 2017 rather than falling by 7%.
View Full
Paper PDF
-
Technology-Driven Market Concentration through Idea Allocation
December 2025
Working Paper Number:
CES-25-78
Using a newly-created measure of technology novelty, this paper identifies periods with and without technology breakthroughs from the 1980s to the 2020s in the US. It is found that market concentration decreases at the advent of revolutionary technologies. We establish a theory addressing inventors' decisions to establish new firms or join incumbents of selected sizes, yielding two key predictions: (1) A higher share of inventors opt for new firms during periods of heightened technology novelty. (2). There is positive assortative matching between idea quality and firm size if inventors join incumbents. Both predictions align with empirical findings and collectively contribute to a reduction in market concentration when groundbreaking technologies occur. Quantitative analysis shows the overall slowdown in technological breakthroughs can capture 95.9% of the rising trend in market concentration and the correlation between the model-generated and the actual detrended market concentration is 0.910.
View Full
Paper PDF
-
How Destructive is Innovation?
January 2017
Working Paper Number:
CES-17-04
Entrants and incumbents can create new products and displace the products of competitors. Incumbents can also improve their existing products. How much of aggregate productivity growth occurs through each of these channels? Using data from the U.S. Longitudinal Business Database on all non-farm private businesses from 1976'1986 and 2003'2013, we arrive at three main conclusions: First, most growth appears to come from incumbents. We infer this from the modest employment share of entering firms (defined as those less than 5 years old). Second, most growth seems to occur through improvements of existing varieties rather than creation of brand new varieties. Third, own-product improvements by incumbents appear to be more important than creative destruction. We infer this because the distribution of job creation and destruction has thinner tails than implied by a model with a dominant role for creative destruction.
View Full
Paper PDF
-
The Spillover Effects of Top Income Inequality
June 2023
Working Paper Number:
CES-23-29
Top income inequality in the United States has increased considerably within occupations. This phenomenon has led to a search for a common explanation. We instead develop a theory where increases in income inequality originating within a few occupations can 'spill over' through consumption into others. We show theoretically that such spillovers occur when an occupation provides non divisible services to consumers, with physicians our prime example. Examining local income inequality across U.S. regions, the data suggest that such spillovers exist for physicians, dentists, and real estate agents. Estimated spillovers for other occupations are consistent with the predictions of our theory.
View Full
Paper PDF
-
The Reallocation Myth
April 2018
Working Paper Number:
CES-18-19
There is a widely held view that much of growth in the U.S. can be attributed to reallocation from low to high productivity firms, including from exiting firms to entrants. Declining dynamism ' falling rates of reallocation and entry/exit in the U.S. ' have therefore been tied to the lackluster growth since 2005. We challenge this view. Gaps in the return to resources do not appear to have narrowed, suggesting that allocative efficiency has not improved in the U.S. in recent decades. Reallocation can also matter if it is a byproduct of innovation. However, we present evidence that most
innovation comes from existing firms improving their own products rather than from entrants or fast-growing firms displacing incumbent firms. Length: 26 pages
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