Effective in 2000, Medicare’s Outpatient Prospective Payment System (OPPS) sets pre-determined reimbursement rates for hospital outpatient services, replacing the prior costbased methods of reimbursement. Using Florida outpatient discharge data, we study the effect of OPPS on hospital...

Researchers often seek to understand the effects of state policies or institutions on individual behavior or other outcomes in sub-state-level observational units (e.g., election results in state legislative districts). However, standard estimation methods applied to such models do not properly...