Protected Area Erasure Accelerates Deforestation in the Brazilian Amazon

This paper estimates the impacts of protected area downsizing and degazettement (PADD) on land-use dynamics in the Brazilian Amazon. Analyzing PADD events implemented between 2009 and 2015, we compare estimates from standard difference-in-differences methods to synthetic difference-in-differences, which addresses violations of parallel trends arising from selective treatment assignment. We show that conventional difference-in-differences estimates yield null effects, consistent with prior literature. Synthetic difference-in-differences estimates, however, show that PADD increases deforestation by approximately 23% relative to pre-treatment baselines, driven by a 40% increase in pastureland expansion and a 3,471% increase in mining area growth. The divergence in results suggests that earlier null findings reflect methodological limitations rather than the absence of actual effects. Our findings underscore the importance of legal protection for environmental outcomes, especially in politically or economically contested areas.