First Author:   Jennifer F Reinganum Department of Economics, Vanderbilt University jennifer.f.reinganum@vanderbilt.edu   415 Calhoun Hall, Vanderbilt University Nashville, 37235, USA   615-322-2937(Phone) 615-322-2937(Fax) Second Author: Andrew F Daughety Department of Economics, Vanderbilt University andrew.f.daughety@vanderbilt.edu   Vanderbilt University, Vanderbilt University Nashville, 37235, USA   615-322-3453(Phone)