International trade, geographic heterogeneity and interregional inequality

Abstract

We study the effect of international trade on interregional income inequality from 1992 to 2012 in the majority of countries worldwide using satellite night-light-based inequality proxies. For our analysis, we develop novel indicators for within-country heterogeneity in trade costs that are based on exogenous geographical features. In order to deal with potential endogeneity issues, we apply a gravity-style instrument that utilizes the occurrence of large natural disasters striking trade partners, as well as a Bartik-style instrument. In contrast to previous studies, our IV estimates reveal that international trade aggravates economic disparities only in those countries that have a higher within-country heterogeneity in terms of their access to the world market and their within-country trade costs.