Comparing IV With Structural Models: What Simple IV Can and Cannot Identify
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We thank Donna Gilleskie, Daniel Schmierer, Greg Veramendi and an anonymous referee for helpful comments. This project was supported by NSF grant SES-0241858, NIH grant R01-HD043411, a grant from the Geary Institute, University College Dublin, and a grant from the American Bar Foundation. The views expressed herein are those of the author(s) and do not necessarily reflect the views of the National Bureau of Economic Research.