Samii, C., Lisiecki, M., Kulkarni, P., Paler, L. and Chavis, L. (2014). “Effects of Payment for Environmental Services (PES) on Deforestation and Poverty in Low and Middle Income Countries: A Systematic Review.” Campbell Systematic Reviews 10: 1–95.
A systematic review of eleven quantitative and nine qualitative studies of payment programs in low and middle income countries, most of them in Latin America. The review finds small effects on deforestation and concludes that there is “little reason for optimism about the potential for current PES approaches to achieve both conservation and poverty reduction benefits jointly.” The wiki uses it as the main test of any claim that inclusion in payment programs lifts households out of poverty: if inclusion moves poverty little, exclusion cannot easily be shown to hold poverty in place.