Combes, Pierre-PhilippeDuranton, GillesOverman, Henry G2023-05-232023-05-232005-08-012016-06-06https://repository.upenn.edu/handle/20.500.14332/45677We consider the literature on urban systems and New Economic Geography to examine questions concerning agglomeration and how areas respond to shocks to the economic environment. We first propose a diagrammatic framework to compare the two approaches. We then use this framework to study a number of extensions and to consider several policy relevant issues.This is the peer reviewed version of the following article: Combes, P. P., Duranton, G. and Overman, H. G. (2005), Agglomeration and the adjustment of the spatial economy. Papers in Regional Science, 84: 311–349., which has been published in final form at doi: 10.1111/j.1435-5957.2005.00038.x. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving: http://olabout.wiley.com/WileyCDA/Section/id-820227.html#terms.urban systemsnew economic geographyurban and regional policydiagrammatic expositionReal EstateArticle