Tomoya Mori, Jens Wrona, 16 August 2019

The gravity equation has often been used to explain trade between regions or cities within countries. But it assumes that the distribution of industries is exogenous. This column explains how trade estimates are affected if we assume that large, centrally located cities attract more industries whose firms are more likely to export to other cities. Japanese data show exports from these cities are systematically underpredicted by aggregate gravity estimations, as the theory predicts.


CEPR Policy Research