This paper develops a quantitative model of internal city structure that features agglomeration and dispersion forces and an arbitrary number of heterogeneous city blocks. The model remains tractable and amenable to empirical analysis because of stochastic shocks to commuting decisions, which...

In this paper we explore to what extent secondary policy issues are influenced by electoral incentives. We develop a political agency model in which a politician decides on both a frontline policy issue, such as the level of public spending, and a secondary policy issue, such as environmental...

One of the most cherished propositions in economics is that market competition by and large raises consumer welfare. But whether political competition has similarly virtuous consequences is far less discussed. This paper formulates a model to explain why political competition may enhance...

This paper reviews a new framework for analyzing the interrelationship between inequality, unemployment, labor market frictions, and foreign trade. This framework emphasizes firm heterogeneity and search and matching frictions in labor markets. It implies that the opening of trade may raise...

This paper reviews the recent theoretical literature on heterogeneous firms and trade, which emphasizes firm selection into international markets and reallocations of resources across firms. We discuss the empirical challenges that motivated this research and its relationship to traditional...

This paper reviews the empirical evidence on firm heterogeneity in international trade. A first wave of empirical findings from micro data on plants and firms proposed challenges for existing models of international trade and inspired the development of new theories emphasizing firm...

This paper reviews the new approach to international trade based on firm heterogeneity in differentiated product markets. This approach explains a variety of features exhibited in disaggregated trade data, including the higher productivity of exporters relative to non-exporters, within-industry...

We develop a quantitative spatial model that incorporates a rich geography of trade and imperfect labor mobility between locations. We provide general results for the existence, uniqueness and comparative statics of the equilibrium. We show how the model can be used to undertake counterfactuals...

While neoclassical theory emphasizes the impact of trade on wage inequality between occupations and sectors, more recent theories of firm heterogeneity point to the impact of trade on wage dispersion within occupations and sectors. Using linked employer-employee data for Brazil, we show that...

We show that endogenous firm selection provides a new welfare margin for heterogeneous firm models of trade (relative to homogeneous firm models). Under some parameter restrictions, the trade elasticity is constant and is a sufficient statistic for welfare, along with the domestic trade share....