[1
]Princeton University, CEPR, CESifo, and NBER
[2
]Harvard University, CEPR, and NBER
[3
]The University of Chicago Booth School of Business, CEPR, and NBER
[4
]Stanford University Graduate School of Business and NBER
[5
]New York University and NBER
[6
]Stanford University Graduate School of Business, CEPR, and NBER
[7
]The University of Chicago Booth School of Business, CEPR, CESifo, and NBER
[8
]Stanford University, CEPR, and NBER