Robalino, Juan, Kwaw S. Andam, Paul J. Ferraro, Alexander Pfaff and G. Arturo Sanchez-Azofeifa. 2008. “Measuring the Effectiveness of Protected Area Networks in Reducing Deforestation: A Rigorous Impact Evaluation Approach.” Proceedings of National Academy of Science 105:42: 16089-16094.
Global efforts to reduce tropical deforestation rely heavily on the establishment of protected areas. Measuring the effectiveness of these areas is difﬁcult because the amount of deforestation that would have occurred in the absence of legal protection cannot be directly observed. Conventional methods of evaluating the effectiveness of protected areas can be biased because protection is not randomly assigned and because protection can induce deforestation spillovers (displacement) to neighboring forests. We demonstrate that estimates of effectiveness can be substantially improved by controlling for biases along dimensions that are observable, measuring spatial spillovers, and testing the sensitivity of estimates to potential hidden biases.