The Dynamics of City Formation
---- Acknowledgements -----
Henderson thanks the Leverhulme foundation for support as a visiting professor at the LSE. Venables' work is supported by the UK ESRC funded Centre for Economic Performance at LSE. The authors thank G. Duranton, E. Rossi-Hansberg, J. Rappaport, R. Serrano, W. Strange, and seminar participants in various forums for helpful comments. The views expressed herein are those of the author(s) and do not necessarily reflect the views of the National Bureau of Economic Research.