We thank the late David Bradford for initiating a conversation that motivated this paper. Our admiration for David’s brilliance as an economist was only exceeded by our admiration for him as a human being. We are grateful for the especially valuable criticisms from David Card and two anonymous referees. Hoyt Bleakley, Tim Conley, Tony Fisher, Michael Hanemann, Enrico Moretti, Marc Nerlove, and Wolfram Schlenker provided insightful comments. We are also grateful for comments from seminar participants at Maryland, Princeton, Yale, the NBER Environmental Economics Summer Institute, and the “Conference on Spatial and Social Interactions in Economics” at the University of California-Santa Barbara. Anand Dash, Elizabeth Greenwood, Barrett Kirwan, Nick Nagle, and William Young, provided outstanding research assistance. We are indebted to Shawn Bucholtz at the United States Department of Agriculture for generously generating weather data for this analysis from the Parameterelevation Regressions on Independent Slopes Model. Finally, we acknowledge The Vegetation/Ecosystem Modeling and Analysis Project and the Atmosphere Section, National Center for Atmospheric Research for access to the Transient Climate database, which we used to obtain regional climate change predictions. Greenstone acknowledges generous funding from the American Bar Foundation.