This paper derives conditions under which preferences and technology are nonparametrically identified in hedonic equilibrium models. With products differentiated along a quality index and agents characterized We thank Guillaume Carlier, Andrew Chesher, Pierre-André Chiappori, Hidehiko Ichimura, Arthur Lewbel, Rosa Matzkin, and multiple seminar audiences for stimulating discussions. We also thank the editor James Heckman and four referees for insightful comments.