Brookings Trade Forum provides comprehensive analysis on current and emerging issues of international trade and macroeconomics. Practitioners and academics contribute to each volume, with papers that provide an in-depth look at a particular topic. The 2008/2009 edition focuses on climate policy and its impact on trade. Contents include • Five "Gs": Lessons for Governing Global Climate from World Trade William Antholis (Brookings) • International Trade Law and the Economics of Climate Policy: Evaluating the Legality and Effectiveness of Proposals to Address Competitiveness and Leakage Concerns Jason E. Bordoff (Brookings) • Technology Transfers and Climate Change: International Flows, Barriers, and Frameworks Thomas L. Brewer (Georgetown University) •Addressing the Leakage / Competitiveness Issue in Climate Change Policy Proposals Jeffrey A. Frankel (Harvard University) • The Economic and Environmental Effects of Border Tax Adjustments for Climate Policy Warwick J. Mckibbin and Peter J.Wilcoxen (Brookings) • The Climate Commons and a Global Environment Organization (GEO) C. Ford Runge (University of Minnesota)

Over the last several decades, rising pay dispersion between firms accounts for the majority of the dramatic increase in earnings inequality in the United States. This paper shows that a distinct cross-cohort pattern drives this rise: newer cohorts of firms enter more dispersed and stay more dispersed throughout their lives. A similar cohort pattern drives a variety of other closely related facts: increases in worker sorting across firms on the basis of pay, education, and age, and increasing productivity dispersion across firms. We discuss two important implications. First, these cohort patterns suggest a link between changes in firm entry associated with the decline in business dynamism and the rise in earnings inequality. Second, cohort effects imply a slow diffusion of inequality: we expect inequality to continue to rise as older and more equal cohorts of firms are replaced by younger and more unequal cohorts. Back of the envelope calculations suggest that this momentum could be substantial with increases in between-firm inequality in the next two decades almost as large as in the last two.

We use administrative data to quantify the firm role in unemployment insurance (UI) take-up. First, there are firm effects in both claiming and appeals, and, consistent with deterrence effects, these are negatively correlated. Second, low-wage workers are less likely to claim and more likely to have their claims appealed than median-wage workers, and firm effects explain a large share of these income gradients. Third, high-claiming and low-appealing firms are desirable firms: they are higher-paying and have lower separation rates. Finally, the dominant source of targeting error in the UI system is that eligible workers do not apply. Our findings emphasize a novel dimension of the role of firms in the labor market, and have implications for the financing of UI.

The Bartik instrument is formed by interacting local industry shares and national industry growth rates. We show that the typical use of a Bartik instrument assumes a pooled exposure research design, where the shares measure differential exposure to common shocks, and identification is based on exogeneity of the shares. Next, we show how the Bartik instrument weights each of the exposure designs. Finally, we discuss how to assess the plausibility of the research design. We illustrate our results through three applications: estimating the elasticity of labor supply, estimating local labor market effects of Chinese imports, and estimating the elasticity of substitution between immigrants and natives.

Displaced workers suffer persistent earnings losses. This stark finding has been established by following workers in administrative data after mass layoffs under the presumption that these are involuntary separations owing to economic distress. This paper examines this presumption by matching survey data on worker-supplied reasons for separations with administrative data. Workers exhibit substantially different earnings dynamics in mass layoffs depending on the reason for separation. Using a new methodology to account for the increased separation rates across all survey responses during a mass layoff, the paper finds earnings loss estimates that are surprisingly close to those using only administrative data.

Displaced workers suffer persistent earnings losses. This stark finding has been established by following workers in administrative data after mass layoffs under the presumption that these are involuntary separations owing to economic distress. This paper examines this presumption by matching survey data on worker-supplied reasons for separations with administrative data. Workers exhibit substantially different earnings dynamics in mass layoffs depending on the reason for separation. Using a new methodology to account for the increased separation rates across all survey responses during a mass layoff, the paper finds earnings loss estimates that are surprisingly close to those using only administrative data.

We study whether reallocating existing teachers across schools within a district can increase student achievement, and what policies would help achieve these gains. Using a model of multi-dimensional value-added, we find meaningful achievement gains from reallocating teachers within a district. Using an estimated equilibrium model of the teacher labor market, we find that achieving most of these gains requires directly affecting teachers' preferences over schools. In contrast, directly affecting principals' selection of teachers can lower student achievement. Our analysis highlights the importance of equilibrium and second-best reasoning in analyzing teacher labor market policies.

This paper estimates workers' preferences for firms by studying the structure of employer-to-employer transitions in U.S. administrative data. The paper uses a tool from numerical linear algebra to measure the central tendency of worker flows, which is closely related to the ranking of firms revealed by workers' choices. There is evidence for compensating differential when workers systematically move to lower-paying firms in a way that cannot be accounted for by layoffs or differences in recruiting intensity. The estimates suggest that compensating differentials account for over half of the firm component of the variance of earnings.

The teacher labor market is a two-sided matching market where the effects of policies depend on the actions of both sides. We specify a matching model of teachers and schools that we estimate with rich data on teachers' applications and principals' ratings. Both teachers' and principals' preferences deviate from those that would maximize the achievement of economically disadvantaged students: teachers prefer schools with fewer disadvantaged students, and principals' ratings are weakly related to teacher effectiveness. In equilibrium, these two deviations combine to produce a surprisingly equitable current allocation where teacher quality is balanced across advantaged and disadvantaged students. To close academic achievement gaps, policies that address deviations on one side alone are ineffective or harmful, while policies that address both deviations could substantially increase disadvantaged students' achievement.

We document three new findings about the industry-level response to minimum wage hikes. First, restaurant exit and entry both rise following a hike. Second, the rise in entry and exit is concentrated in chains. Third, there is no change in employment among continuing restaurants. We develop a model of industry dynamics based on putty-clay technology and show that it is consistent with these findings. In the model, continuing restaurants cannot change employment, and thus industry-level adjustment occurs through exit of labor-intensive restaurants and entry of capital-intensive ones. We show these three findings are inconsistent with other models of industry dynamics.