The present paper focuses on sorting as a mechanism behind the well-established fact that there is a central region productivity premium. Using a model of heterogeneous firms that can move between regions, Baldwin and Okubo (2006) show how more productive firms sort themselves to the large core...

This paper compares two policies: trade cost reduction and firm relocation cost reduction using a three-country version of a heterogeneous-firms economic geography model, where the three countries have different market (population) size. We show how the effects of the two policies differ, in...