Economies of scale and the size of exporters

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). The authors 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. It is easy to reconcile the model with the data. However, a lot of variation independent of firm size is needed to do so. This suggests that economies of scale play only a minor role in determining a firm's export status. The authors show that the augmented model also has markedly different implications in the event of a trade liberalization. Most of the adjustment is through the intensive margin and productivity gains due to reallocation are halved.