Fig. 3.

Do protected area systems exacerbate poverty? Poverty rates in 2000 were, on average, higher near Costa Rica and Thailand protected areas, seemingly suggesting that protected area systems have exacerbated poverty (dark bars). However, estimates using matching methods to control for differences in baseline characteristics that affect both poverty and the location of protected areas indicate that protected areas have alleviated poverty (lighter bars). Bars refer to 95% confidence intervals. Standard errors for matching estimates were calculated using the robust variance formula in ref. 27. A t test is used to assess the difference in means between treated and control units. Asterisks refer to tests of the null hypothesis of zero impact (**, P < 0.05; ***, P < 0.01). Costa Rica sample: N treated = 249; N control = 4164; N treated dropped by calipers = 22. Thailand sample: N treated = 192; N control = 3479; N treated dropped by calipers = 48.