Upward mobility. A gilded temple in northern Thailand near the Chiang Dao National Park.

K. Sims

Animal Reserves Can Be Good for People, Too

Creating a national park or other reserve can help protect animals and plants. But what about the people who live in the area? A new study of Costa Rica and Thailand suggests that neighbors are better off economically than people who don't have parks nearby.

The study isn't the final word in this contentious debate, but it does set a new benchmark for rigorous analysis. "This is a well-crafted study," says conservation biologist Stuart Pimm of Duke University in Durham, North Carolina. "I can't think of any others this good."

The question of how new parks affect people living near them is "arguably the most controversial debate in conservation policy," according to the authors of the new paper. Parks often prohibit farming and hunting, so they might reduce the income of villagers nearby. On the other hand, they can create new jobs for game wardens or tour guides, as well as new roads. Although some studies have found anecdotal evidence for worsened poverty, they have not eliminated potentially confounding factors, says Paul Ferraro, an economist at Georgia State University in Atlanta. For example, parks are often established in remote areas where poverty is already a problem.

Ferraro and his colleagues turned to Thailand and Costa Rica for their reliable, long-term data on household assets and other indicators of poverty. When the researchers simply compared communities near parks with communities elsewhere, they found that poverty was worse near parks. But when they controlled for the confounding factors— comparing only communities with similar agricultural productivity, for example—there was 30% less poverty near the parks in Thailand. (In Costa Rica, about 10% of the decline in a measure of poverty was due to the presence of protected areas.) "We were surprised by the robustness of these results," says Ferraro, whose team describes the findings online today in the Proceedings of the National Academy of Sciences.

There are a number of caveats. The study examined average poverty rates across the community, so not all households near a park may have become better off. And the findings may not apply to other developing countries; Thailand and Costa Rica have both had relatively stable governments and have invested in parks and ecotourism.

William Adams, a geographer at the University of Cambridge in the United Kingdom, says that a broad conclusion about the impact of parks is unlikely. Some parks may improve poverty whereas others worsen it. Finding out why some parks benefit their neighbors is crucial to improving the effectiveness of environmental policy, he says. Ferraro says his team is trying to answer that question.