Mark Doms

Understanding Productivity: Lessons from Longitudinal Microdata

This paper reviews research that uses longitudinal microdata to document productivity movements and to examine factors behind productivity growth. The research explores the dispersion of productivity across firms and establishments, the persistence of productivity differentials, the consequences of entry and exit, and the contribution of resource reallocation across firms to aggregate productivity growth. The research also reveals important factors correlated with productivity growth, such as managerial ability, technology use, human capital, and regulation. The more advanced literature in the field has begun to address the more difficult questions of the causality between these factors and productivity growth.

Women in STEM: A Gender Gap to Innovation

Our science, technology, engineering and math (STEM) workforce is crucial to America’s innovative capacity and global competitiveness. Yet women are vastly underrepresented in STEM jobs and among STEM degree holders despite making up nearly half of the U.S. workforce and half of the college-educated workforce. That leaves an untapped opportunity to expand STEM employment in the United States, even as there is wide agreement that the nation must do more to improve its competitiveness.Although women fill close to half of all jobs in the U.S. economy, they hold less than 25 percent of STEM jobs. This has been the case throughout the past decade, even as college-educated women have increased their share of the overall workforce.Women with STEM jobs earned 33 percent more than comparable women in non-STEM jobs – considerably higher than the STEM premium for men. As a result, the gender wage gap is smaller in STEM jobs than in non-STEM jobs.Women hold a disproportionately low share of STEM undergraduate degrees, particularly in engineering.Women with a STEM degree are less likely than their male counterparts to work in a STEM occupation; they are more likely to work in education or healthcare.There are many possible factors contributing to the discrepancy of women and men in STEM jobs, including: a lack of female role models, gender stereotyping, and less family-friendly flexibility in the STEM fields. Regardless of the causes, the findings of this report provide evidence of a need to encourage and support women in STEM.

Should the Personal Computer Be Considered a Technological Revolution? Evidence from U.S. Metropolitan Areas

The introduction and diffusion of personal computers are widely viewed as a technological revolution. Using U.S. metropolitan area–level panel data, this paper asks whether links between PC adoption, educational attainment, and the return to skill conform to a model of technological revolutions in which the speed and extent of adoption are endogenous. The model implies that cities will adjust differently to the arrival of a more skill-intensive means of production, with the returns to skill increasing most where skill is abundant and its return is low. We show that the cross-city data fit many of the predictions of the model during the period 1980–2000, the PC diffusion era.

Endogenous Skill Bias in Technology Adoption: City-Level Evidence from the IT Revolution

This paper focuses on the bi-directional interaction between technology adoption and labor market conditions. We examine cross-city differences in PC adoption, relative wages, and changes in relative wages over the period 1980-2000 to evaluate whether the patterns conform to the predictions of a neoclassical model of endogenous technology adoption. Our approach melds the literature on the effect of the relative supply of skilled labor on technology adoption to the often distinct literature on how technological change influences the relative demand for skilled labor. Our results support the idea that differences in technology use across cities and its effects on wages reflect an equilibrium response to local factor supply conditions. The model and data suggest that cities initially endowed with relatively abundant and cheap skilled labor adopted PCs more aggressively than cities with relatively expensive skilled labor, causing returns to skill to increase most in cities that adopted PCs most intensively. Our findings indicate that neoclassical models of endogenous technology adoption can be very useful for understanding where technological change arises and how it affects markets.

Information technology investment and firm performance in US retail trade

We examine the relationship between investments in information technology (IT) and retail firm performance. We use untapped firm and establishment micro data from the Censuses of Retail Trade and the Assets and Expenditures Survey. We show that large firms account for most retail IT investment, employment, and establishment growth. We find evidence of a significant relationship between IT investment intensity and productivity growth. E-mail: ron.s.jarmin@census.gov E-mail: mark.doms@sf.frb.org

Innovations in Mortgage Markets and Increased Spending on Housing

Over the past several decades, innovations in the mortgage market have benefited consumers through a variety of channels. Innovations include the lowering of down payment requirements, increased flexibility in repayment schedules, and the reduction of costs associated with extracting equity from homes. To ascertain the ways in which these innovations would alter spending on housing, we develop a model of the home buying and mortgage choice decision that produces a number of testable implications. For instance, the lowering of down payment requirements should result in homeownership rates increasing, especially for households that are traditionally cash constrained. In fact, we show that between 1994 and 2004, the homeownership rate for young and low-income households rose sharply. Increased flexibility of repayment schedules should assist households in smoothing their housing consumption choices. Empirically, we document that households have increased the share of their income spent on housing by a substantial margin. The result is robust to the changing composition of households and also to regional location. Households that have been traditionally cash constrained have increased their housing expenditures but tend to have low mortgage rates, suggesting that these households may be financing their increased housing consumption with alternative, flexible mortgage products.

How Fast do Personal Computers Depreciate? Concepts and New Estimates

This paper provides new estimates of depreciation rates for personal computers using an extensive database of prices of used PCs. Our results show that PCs lose roughly half their remaining value, on average, with each additional year of use. We decompose that decline into age-related depreciation and a revaluation effect, where the latter effect is driven by the steep ongoing drop in the constant-quality prices of newly-introduced PCs. Our results are directly applicable for measuring the depreciation of PCs in the National Income and Product Accounts (NIPAs) and were incorporated into the December 2003 comprehensive NIPA revision. Regarding tax policy, our estimates suggest that the current tax depreciation schedule for PCs closely tracks the actual loss of value in a zero-inflation environment. However, because the tax code is not indexed for inflation, the tax allowances would be too small in present value for inflation rates above the very low level now prevailing.

Labor Supply and Personal Computer Adoption

The positive correlations found between computer use and human capital are often interpreted as evidence that the adoption of computers have raised the relative demand for skilled labor, the widely touted skill-biased technological change hypothesis. However, several models argue the skill-intensity of technology is endogenously determined by the relative supply of skilled labor. We use instruments for the supply of human capital coupled with a rich dataset on computer usage by businesses to show that the supply of human capital is an important determinant of the adoption of personal computers. Our results suggest that great caution must be exercised in placing economic interpretations on the correlations often found between technology and human capital.

When do Matched-model and Hedonic Techniques Yield Similar Measures?

Hedonic techniques were developed to control for quality differences across goods and over time in order to construct constant-quality aggregate price measures. When the available data are a panel of high-frequency data on models whose characteristics are constant over time, matched-model price indexes can also be used to obtain constant quality price measures. We show this by demonstrating that, given data of this type, certain matched-model indexes yield price measures that are numerically close to those obtained using hedonic techniques. ; * This paper is a condensed version of a paper that was presented at the CRIW workshop on Price Measurement at the NBER Summer Institute, July 31-August 1, 2000 and is available at http://www.nber.org.

Education Supports Racial and Ethnic Equality in STEM

Science, technology, engineering, and math (STEM) workers are essential to American innovation and competitiveness in an increasingly dynamic and global marketplace. In this report, we examine demographic disparities in STEM education and find that educational attainment may affect equality of opportunity in these critical, high-quality jobs of the future.We find that regardless of race and Hispanic origin, higher college graduation rates are associated with higher shares of workers with STEM jobs. But non-Hispanic Whites and Asians are much more likely than other minority groups to have a bachelor’s degree. Other key findings of this report include: Non-Hispanic Whites comprise the largest group of STEM workers, accounting for about seven out of ten STEM worker, which aligns closely with their share of the overall workforce; Non-Hispanic Asians are most likely (42 percent) to graduate college with a STEM degree, while the propensities of other groups are fairly similar (17-22 percent); half of all non-Hispanic Asian workers with STEM degrees have STEM jobs, compared to 30% of Hispanics and non-Hispanic Black and American Indian and Alaska Native workers; one in five STEM workers is foreign-born, of which 63 percent come from Asia; STEM workers in all demographic groups, including the foreign-born, earn more than their non-STEM counterparts. Hispanics and non-Hispanic Blacks receive a significantly larger STEM premium than do non-Hispanic Whites.