The movement of activity, usually industry, away from agglomerations, perhaps when congestion makes further agglomeration in a region difficult and expensive. See Werker and Athreye (2004) J. Evol. Econ. 14 on deglomeration, agglomeration, and evolutionary economic geography. Deglomeration economies, such as lower transport costs, or longer commuting times and congestion externalities (Y. Kanemoto et al. 2005), lead to decentralization.