Trade Policy as an Exogenous Shock: Focusing on the Specifics

This paper proposes a novel strategy for identifying the effects of import competition on economic outcomes that avoids standard concerns related to the endogeneity of trade policy and provides a consistent measure of exposure to trade over time. Conditioning on the level of import tariffs, our approach exploits cross-industry differences in the relative importance of specific rather than ad valorem tariffs. As they are expressed in per unit terms rather than as a share of value, the effective protection provided by a given specific tariff varies with price levels. Using digitized tariff line data between 1900 and 1940, we relate inflation-driven changes in trade protection to changes in imports and labor market outcomes in the full count U.S. census. We show that our measure predicts import growth at both the industry and county level. Using our measure as an instrument, we show that import competition reduces labor force participation in traded sectors during this period. Labor market effects are widespread but fall most heavily on those with little experience or fewer outside labor market options: the young, seniors, and those in rural areas

Who Benefits from a Minimum Wage Increase?

This paper addresses the question of how a minimum wage increase affects the wages of low-wage workers. Most studies assume that there is a simple mechanical increase in the wage for workers earning a wage between the old and the new minimum wage, with some studies allowing for spillovers to workers with wages just above this range. Rather than assume that the wages of these workers would have remained constant, this paper estimates how a minimum wage increase impacts a low-wage worker’s wage relative to the wage the worker would have if there had been no minimum wage increase. The method allows for the effect to depend not only on the initial wage of the worker, but also nonlinearly on the size of the minimum wage increase. Using Current Population Survey data from 2005 to 2008, a period with a large number of U.S. state-level minimum wage increases, this paper finds that low-wage workers who experience a small increase in the minimum wage tend to have lower wage growth than if there had been no minimum wage increase. A large increase to the minimum wage increases the wages of not only those workers who previously earned less than the new minimum wage, but also spill over to workers with moderately higher wages. Finally, this paper finds little evidence of heterogeneity in the effect by age, gender, income, and race

Who Benefits from a Minimum Wage Increase?

This paper addresses the question of how a minimum wage increase affects the wages of low-wage workers. Most studies assume that there is a simple mechanical increase in the wage for workers earning a wage between the old and the new minimum wage, with some studies allowing for spillovers to workers with wages just above this range. Rather than assume that the wages of these workers would have remained constant, this paper estimates how a minimum wage increase impacts a low-wage worker’s wage relative to the wage the worker would have if there had been no minimum wage increase. The method allows for the effect to depend not only on the initial wage of the worker, but also nonlinearly on the size of the minimum wage increase. Using Current Population Survey data from 2005 to 2008, a period with a large number of U.S. state-level minimum wage increases, this paper finds that low-wage workers who experience a small increase in the minimum wage tend to have lower wage growth than if there had been no minimum wage increase. A large increase to the minimum wage increases the wages of not only those workers who previously earned less than the new minimum wage, but also spill over to workers with moderately higher wages. Finally, this paper finds little evidence of heterogeneity in the effect by age, gender, income, and race

How a Diverse Research Ecosystem Has Generated New Rehabilitation Technologies: Review of NIDILRR’s Rehabilitation Engineering Research Centers

Over 50 million United States citizens (1 in 6 people in the US) have a developmental, acquired, or degenerative disability. The average US citizen can expect to live 20% of his or her life with a disability. Rehabilitation technologies play a major role in improving the quality of life for people with a disability, yet widespread and highly challenging needs remain. Within the US, a major effort aimed at the creation and evaluation of rehabilitation technology has been the Rehabilitation Engineering Research Centers (RERCs) sponsored by the National Institute on Disability, Independent Living, and Rehabilitation Research. As envisioned at their conception by a panel of the National Academy of Science in 1970, these centers were intended to take a “total approach to rehabilitation”, combining medicine, engineering, and related science, to improve the quality of life of individuals with a disability. Here, we review the scope, achievements, and ongoing projects of an unbiased sample of 19 currently active or recently terminated RERCs. Specifically, for each center, we briefly explain the needs it targets, summarize key historical advances, identify emerging innovations, and consider future directions. Our assessment from this review is that the RERC program indeed involves a multidisciplinary approach, with 36 professional fields involved, although 70% of research and development staff are in engineering fields, 23% in clinical fields, and only 7% in basic science fields; significantly, 11% of the professional staff have a disability related to their research. We observe that the RERC program has substantially diversified the scope of its work since the 1970’s, addressing more types of disabilities using more technologies, and, in particular, often now focusing on information technologies. RERC work also now often views users as integrated into an interdependent society through technologies that both people with and without disabilities co-use (such as the internet, wireless communication, and architecture). In addition, RERC research has evolved to view users as able at improving outcomes through learning, exercise, and plasticity (rather than being static), which can be optimally timed. We provide examples of rehabilitation technology innovation produced by the RERCs that illustrate this increasingly diversifying scope and evolving perspective. We conclude by discussing growth opportunities and possible future directions of the RERC program

Essays in applied microeconomics

This dissertation consists of three essays. The first essay examines the manner in which firms adjust product portfolios when exposed to trade. The second examines the wage growth effects of changes in minimum wage laws. The final essay analyzes changes in dropout rates in communities exposed to import competition from China The first essay examines how firms adjust product offerings in the face of changing trade costs. A recent theoretical literature has emphasized the magnitude and importance of multiproduct firms in trade. However, models within this literature have reached contradictory conclusions regarding the within-firm product diversification response to changes in trade costs. This paper attempts to resolve these contradictions by employing Bayesian techniques to estimate diversification responses, and the manner in which they differ across firms depending upon sales and export orientation. I analyze the adjustment of diversification levels of public US manufacturing firms in the period immediately preceding and following the Canada-US free trade agreement of 1989. I find evidence of a differential response among firms that are heterogeneous in terms of export orientation. Firms with less than 16 percent of sales in international segments reduce diversification following a reduction in trade costs, while more export-oriented firms increase diversification. Bayesian model comparison supports this finding. The data does not support a differential response when heterogeneity in firm sales is considered. The second essay, written jointly with Kevin Mumford, addresses the question of how a minimum wage increase affects the wages of low-wage workers. Most studies assume that there is a simple mechanical increase in the wage for workers earning a wage between the old and the new minimum wage with some studies allowing for spillovers to workers with wages just above this range. Rather than assume that the wages of these workers would have remained constant, this paper estimates how a minimum wage increase impacts a low-wage workers\u27 wage relative to the wage the worker would have if there had been no minimum wage increase. The method allows for the effect to depend not only on the initial wage of the worker, but also nonlinearly on the size of the minimum wage increase. Using Current Population Survey data from 2005 to 2008, a period with a large number of state-level minimum wage increases, this paper finds that low-wage workers are hurt by a small minimum wage increase. Larger minimum wage increases benefit not only those workers directly affected but spill over to workers with moderately higher wages. Finally, this paper finds evidence for heterogeneity in the effect by age, gender, income, and race. The final essay, written jointly with Andrew Greenland, exploits regional variation in exposure to Chinese import competition to identify the effect of trade-induced changes in labor market conditions on U.S. high school dropout rates. Employing the methodology of Autor et al. (2013), who examine the effect of increased Chinese import competition on U.S. employment and wages, we argue that increasing import competition increases the relative returns to education and leads to a reduction in dropout rates. For the region with the median dropout rate in 2000, a movement from the 25th to the 75th percentile of change in import exposure per worker corresponds to a reduction in the 2007 dropout rate by .456 percentage points, which corresponds to a reduction in the number of dropouts by over 68,000 annually. Using available estimates of the present value of the lifetime net public benefit of each additional high school graduate and extrapolating such an annual reduction in dropouts to the entire country implies a net public benefit between $4.4 billion and$14.4 billion. Results are robust to controls for changes in school quality, demographic composition, and initial labor market conditions

Unringing the Bell? The Asymmetric Effects of Trade Policy

The proposed paper will explore the potentially nonlinear employment, wage, and output responses to changes in tariff rates, and how such responses depend upon the magnitude and direction of the change. While the extant literature has analyzed the consequences of trade liberalization for labor market outcomes, little attention has been given to the effects of subsequent reversals in tariff policy. We will collect and digitize annual U.S. tariff rates at the tariff-line level between 1909 and 1937, a period of substantial volatility in U.S. trade policy, featuring both periods of liberalization and increased protectionism. Using recently developed dynamic panel threshold models, we will explore whether the effects of reduced trade barriers on wages, employment, and other labor market outcomes are similar in magnitude to those of subsequent increases in those barriers. This issue is of increasing importance given recent increases in protectionist sentiment, most notably in Europe and the U.S

Larger and faster: revised properties and a shorter orbital period for the WASP-57 planetary system from a pro-am collaboration

Transits in the WASP-57 planetary system have been found to occur half an hour earlier than expected. We present 10 transit light curves from amateur telescopes, on which this discovery was based, 13 transit light curves from professional facilities which confirm and refine this finding, and high-resolution imaging which show no evidence for nearby companions. We use these data to determine a new and precise orbital ephemeris, and measure the physical properties of the system. Our revised orbital period is 4.5 s shorter than found from the discovery data alone, which explains the early occurrence of the transits. We also find both the star and planet to be larger and less massive than previously thought. The measured mass and radius of the planet are now consistent with theoretical models of gas giants containing no heavy-element core, as expected for the subsolar metallicity of the host star. Two transits were observed simultaneously in four passbands. We use the resulting light curves to measure the planet's radius as a function of wavelength, finding that our data are sufficient in principle but not in practise to constrain its atmospheric properties. We conclude with a discussion of the current and future status of transmission photometry studies for probing the atmospheres of gas-giant transiting planets