Trade policy under firm-level heterogeneity in a small economy

We explore the effect of trade policy on productivity and welfare in the now standard model of firm-level heterogeneity and product differentiation with monopolistic competition. To obtain sharp results, we restrict attention to an economy that takes as given the price of imports and the demand schedules for its exports (a “small economy”). We first establish that welfare can be decomposed into four terms: productivity, terms of trade, variety …