I would like to thank Ran Spiegler for his helpful suggestions. I am also grateful to Miguel Angel Ballester, Johannes Hoerner, Philippe Jehiel, Erika Magnago, Paola Manzini, Marco Mariotti, William Neilson, an anonymous referee, the editor Nicholas C. Yannelis, and the seminar audience at Aberdeen and UCL for their comments. Any error is my own responsibility.Peer reviewedPreprin