Skip to main content We received helpful comments from: Rodney Andrews, Shubhashrita Basu, Lee Benham, Ashutosh Bhuradia, Bobby Chung, William Dougan, Susan Dynarski, Robert Fleck, Ian Fillmore, Jeffrey Gray, Majid Hashemi, Kirabo Jackson, Kendall Kennedy, Salman Khan, John List, Jonathan Meer, Benjamin Posmanick, Jesse Shapiro, Kent Smetters, Betsey Stevenson, Sounak Thakur, Alessandra Voena, Kenneth Whaley, Arkādijs Zvaigzne; and seminar participants at the Economics Graduate Students'...