Identifying Agglomeration Shadows: Long-run Evidence from Ancient Ports

For helpful comments and suggestions, we thank many colleagues and seminar and conference participants at Bergamo, Berlin, Bern, Bristol, BU, CEU, Census, Dartmouth, FRB-Philadelphia, GEA, Georgetown, Harvard, Humboldt, Konstanz, LSE, NUS, Ottawa, Oxford, PSE, RES, UChicago, UEA, Warwick, Wash U, Yale, and York. In particular, we thank Amir Jina for early conversations, along with Jeffrey Lin and Tomoya Mori. For helpful discussant comments, we thank Arieda Mu�o and Kohei Takeda. We thank Arthur de Graauw for very helpful advice on using his data on ancient port locations. For excellent research assistance, we thank Sam Abers, Olivia Bordeu Gazmuri, Loughlan O'Doherty, Georgios Tzortzis, Natalie Yang, and the team at Digital Divide Data. This research was funded in part by the Initiative on Global Markets at the University of Chicago Booth School of Business, the Neubauer Family Faculty Fellowship, and the ESRC's Centre for Economic Performance. The views expressed herein are those of the authors and do not necessarily reflect the views of the National Bureau of Economic Research.