The Effect of Trade on Agglomeration within Regions

This paper assesses for the first time the effect of regional trade openness on agglomeration within regions, using regional data on the trade of Colombia. The results of the panel model show that the effect of trade is sufficiently strong to shape the spatial configuration, a structure that rarely changes. The effect varies across regions. On the one hand, trade enhances spatial agglomeration within regions with large home market and location advantages. On the other hand, trade induces dispersion within regions that lack access to international trade or historical advantage. These results hold when controlling for the natural course of agglomeration (region-specific time trends), congestion effects in main cities and road infrastructure within regions.