1. Department of Economics and Business, Universitat Pompeu Fabra Roma Trias Fargas 25-27, 08005 Barcelona, Spain, and Barcelona GSE, CREI, and CEPR (e-mail: )
2. University of Michigan, 611 Tappan Street, Ann Arbor, MI 48109, NBER and CEPR (e-mail: )
3. Federal Reserve Bank of Chicago, 230 South LaSalle Street, Chicago, IL 60604 (e-mail: )