This paper employs a difference-in-differences framework to estimate the effects of mandatory managed care restrictions implemented during Puerto Rico's 1993 healthcare reform. The reform replaced the island's unrestricted universal healthcare model with a privatized system, introducing closed provider networks, mandatory gate-keeping requirements, and capitation-based payment structures that shifted financial risk to providers. Exploiting the staggered rollout of the reform across 78 municipalities in five cohorts from 1994 to 2000, I identify causal effects on healthcare labor markets, patient utilization patterns, and health outcomes.

This paper fills a gap in the place-based policy literature by examining the consequences of withdrawing industrial incentives—a question largely unexplored despite extensive research on policy implementation. The project exploits the phase-out and elimination of IRS Section 936 in Puerto Rico, which exempted U.S. corporations from federal taxes on island profits, as a quasi-experimental shock to identify causal effects on local labor markets. Using synthetic difference-in-differences, we estimate the effect of lifting this policy on local labor market outcomes. Our findings reveal that the phaseout (1996) and eventual elimination (2006) led to significant manufacturing job losses, with the phaseout generating an average decrease of approximately 9.2% in manufacturing employment by 2000 and an average decrease of 28% following elimination by 2019, relative to a counterfactual in which the policy remained.