Among conservationists, policy-makers, and the public, there is great debate about whether the establishment of national parks and reserves in developing nations causes poverty or helps to alleviate it. While opponents claim that protected areas limit agricultural development and the harvesting of natural resources, supporters contend that protected areas generate tourism income and improve infrastructure in the surrounding areas. A new study in PNAS this week suggests that, in the long term, establishing protected areas in developing nations does reduce poverty in local communities.

The authors criticize earlier studies that have found correlations between poverty and protected areas for omitting confounding variables that may account for the apparent link. Since many biodiversity hotspots are located in poverty-stricken areas, the local communities are usually poor at the inception of the national park or reserve. Furthermore, these areas are often located in relatively remote geographical regions where economic progress is slow. To control for these variables, the PNAS study used a matching method to compare areas with similar economic and geographical characteristics to determine how communities would be faring today if nearby protected areas had not been established.

In order to assess long-term impacts, the study focused on parks and reserves created 15 or more years ago, in both Costa Rica and Thailand. Communities were considered “treated” if greater than 10 percent of their land area was protected; controls had less than 1 percent protected area. Treated communities were matched with control communities based on preprotection poverty, forest cover, land productivity, and access to transportation. They were then compared in terms of their current poverty index or poverty headcount (the percent of the population which falls below the poverty line) to determine the economic impact of the protected area.

When these confounding variables were controlled for, the results showed that the communities surrounding protected areas actually enjoyed reduced poverty compared to the control communities. In Costa Rica, the protected areas were responsible for about 10 percent of the observed poverty reduction, and the effect was even greater in Thailand, where about 30 percent of the poverty reduction was attributable to nearby parks and reserves.

These results were quite robust, holding true even when the threshold for the protected land in treated communities was increased fivefold to 50 percent of the area. Furthermore, the authors were able to rule out other explanations for the findings, such as the claim that protected areas force poor people to leave the region, and the possibility that protection has negative impacts on nearby control communities.

The authors do recognize a few limitations of the work. First, the goal of the research was to assess long-term effects, so the short-term implications of protected areas are not addressed in the study. Additionally, the authors do not speculate about the mechanisms involved in reducing poverty. Finally, since this is a large study that tracked generalized trends across many communities, the results will not necessarily hold true in every area. This last caveat is especially important, since both Costa Rica and Thailand have several characteristics in common that other countries with biodiversity hotspots may not.

Despite the caveats, this study is a definite improvement upon the earlier research that failed to control for confounding factors. Since other studies in Thailand and Costa Rica have found that the establishment of protected areas reduces deforestation, perhaps the most uplifting implication of this study is that conservation can contribute simultaneously to sustainability and poverty reduction in developing nations.

PNAS, 2010. DOI: 10.1073/pnas.0914177107 (About DOIs).

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