International Trade

A Balls-and-Bins Model of Trade

with Miklos Koren.

A number of stylized facts have been documented about the extensive margin of trade---how many products countries or firms send to how many destinations. We argue that several of these facts are driven by the sparse nature of trade data and fail to identify the relevant model of the extensive margin. Typically the number of observations---that is, total shipments---is low relative to the number of possible classifications---e.g., destinations and product codes.

Economies of Scale and the Size of Exporters

with Miklos Koren.

Exporters are few---less than one-fifth among U.S. manufacturing firms---and are larger than non-exporting firms---about 4-5 times more total sales per firm. These facts are often cited as support for models with economies of scale and firm heterogeneity as in Melitz (2003). We find that the basic Melitz model cannot simultaneously match the size and share of exporters given the observed distribution of total sales. Instead exporters are expected to be between 90 and 100 times larger than non-exporters.