There is a large body of evidence indicating that cross-country differences in income levels are associated with differences in productivity. If workers are much more productive in one country than in another, restrictions on immigration lead to large efficiency losses. The paper quantifies...

We show in a multi-sector, heterogeneous-firm trade model that the effect of tariffs on entry, especially in the presence of production linkages, can reverse the traditional positive optimal tariff argument. We then use a new tariff dataset, and apply it to a 189-country, 15-sector version of...

Casual empiricism suggests that additive trade costs, such as quotas, per-unit tariffs, and, in part, transportation costs, are prevalent. In spite of this, we have no broad and systematic evidence of the magnitude of these costs. We develop a new empirical framework for estimating additive...

If trade barriers are managed by inefficient institutions, trade liberalization can lead to greater-than-expected gains. We examine Chinese textile and clothing exports before and after the elimination of externally imposed export quotas. We find that the surge in export value and decline in...

In this paper I analyze the productivity gains from trade liberalization in the Belgian textile industry. So far, empirical research has established a strong relationship between opening up to trade and productivity, relying almost entirely on deflated sales to proxy for output in the production...

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...

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....

We formulate a two-country model with monopolistic competition and heterogeneous firms to reconsider labor market linkages in open economies. Labor-market imperfections arise by virtue of country-specific real minimum wages. Two principal experiments are considered. First, we show that trade...