The next RITM Economics Seminar will take place on Monday 5 november, in Gaudemet (Jean Monnet – 54 boulevard Desgranges – 92330 Sceaux) from 12:00 to 13:00. Laurent Gobillon (PSE) will present “Delineating urban areas using building density” (co-writting with Marie-Pierre de Bellefon, Pierre-Philippe Combes, et Gilles Duranton).
Abstract: We develop a new dartboard methodology to delineate urban areas using detailed information about building location, which we implement using a map of buildings in France. For each pixel, our approach compares actual building density after smoothing to counterfactual smoothed building density computed after randomly redistributing buildings. We define as urban any area with statistically significant excess building density. We also define the urban cores of these urban areas in a similar manner. Finally, we develop novel one- and twosided tests to provide a statistical basis to compare maps with different delineations, which we use to document the robustness of our approach and large differences between our preferred delineation and the corresponding official one.