NBER Publications by Costas Arkolakis

I develop a new theory of marketing costs and introduce it into a model of trade with product differentiation and firm productivity heterogeneity. In this model, a firm enters a market if it makes profits by reaching a single consumer there and pays an increasing marginal cost to access additional consumers. This market penetration cost introduces an extensive margin of new consumers in firms' sales. I calibrate the key parameters of the model to match data on French firms from Eaton, Kortum and Kramarz, in particular the higher sales in France of firms that choose to export to more destinations. The model predicts that most firms do not export, and that a large proportion of firms that export in particular markets do so in small amounts. These predictions are in line with the French da...

We explore the implications of models with increasing returns, endogenous variety and firm-level heterogeneity for the quantification of the gains from trade. We first focus on the impact of trade liberalization on imported variety by analyzing the experience of Costa Rica from 1986 to 1992. We find that although liberalization triggered a sizable increase in variety, the resulting welfare gains were small because of strong heterogeneity across imported goods. Upon trade liberalization, the new varieties are imported in small quantities, and hence contribute little to welfare. We then present a model with firm-level increasing returns, differentiated goods, monopolistic competition, endogenous variety and free entry to show that total variety (domestic plus imported) can either increase, d...