Janet Currie1,2, Molly Schnell3,4. 1. Department of Economics, Princeton University, Princeton, NJ, USA. jcurrie@princeton.edu. 2. National Bureau of Economic Research, Cambridge, MA, USA. jcurrie@princeton.edu. 3. National Bureau of Economic Research, Cambridge, MA, USA. 4. Department of Economics, Northwestern University, Evanston, IL, USA.