Biographical note: Richard Baldwin is Professor of International Economics at the Graduate Institute of International Economics in Geneva. Rikard Forslid is Associate Professor of Economics at Stockholm University. Philippe Martin is Professor of Economics at the University of Paris 1...

Research on the spatial aspects of economic activity has flourished over the past decade due to the emergence of new theory, new data, and an intense interest on the part of policymakers, especially in Europe but increasingly in North America and elsewhere as well. However, these...