First Author:   Robert Feinberg American University feinber@american.edu   Department of Economics, American University, 4400 Massachusetts Avenue, NW Washington, 20016-8029, U.S.A.   202-885-3788(Phone) 202-885-3788(Fax) Second Author: Christopher Snyder George Washington University cmsnyder@gwu.edu   Department of Economics, George Washington University, 2201 G Street, NW Washington, 20052, U.S.A.   202-994-6581(Phone) 202-994-6147(Fax)