NBER Working Paper No. 22727
---- Acknowledgements ----
This paper was commissioned for the Journal of Economic Literature. We are grateful to Janet Currie and Steven Durlauf for their encouragement. We would like to thank Steven Durlauf, six referees, Pol Antras, Joaquin Blaum, Peter Neary, David Weinstein and conference and seminar participants at CEPR, NOITS, Oxford and UIBE for helpful comments. Bernard, Jensen, Redding and Schott thank Tuck, Georgetown, Princeton and Yale respectively for research support. We thank Jim Davis from Census for handling disclosure. The empirical research in this paper was conducted at the Boston, New York and Washington U.S. Census Regional Data Centers. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the U.S. Census Bureau, the National Bureau of Economic Research, the Centre for Economic Policy Research, the National Bureau of Economic Research, or any other institution to which the authors are affiliated. Results have been screened to ensure that no confidential data are revealed.