Ecotourism efforts in Costa Rica have led to decreased poverty levels in regions near protected parks and natural areas, according to a new study.

Writing in the Proceedings of the National Academy of Sciences, a research team reports that the effects of environmental programs on social outcomes are not well understood, but that in Costa Rica, the protected area system has reduced poverty in communities surrounding the protected areas.

The study found that nearly two-thirds of the poverty reduction in the regions can be attributed to opportunities afforded by tourism.

Earlier research had linked the establishment of protected areas in poor regions with a reduction in poverty, but there was no clear understanding of why or how that was happening.

"Our goal was to show exactly how environmental protection can reduce poverty in poorer nations rather than exacerbate it, as many people fear," said study co-author Paul Ferraro, a professor of economics and environmental policy at Georgia State University.

Ferraro and his collaborators examined three potential triggers for poverty reduction linked to the establishment of protected areas: 1.) changes in tourism and recreational services, 2.) changes in infrastructure including roads, health clinics and schools and 3.) changes in ecosystem services such as the pollination and hydrological services a protected area may offer.

In addition to learning that nearly 66 percent of poverty reduction was linked to changes in tourism and recreational services, the researchers found that changes in infrastructure and land use had little effect on the poverty in surrounding communities.

"Our results suggest that by using existing data sets such as poverty estimates from census data, the impacts of conservation programs and policies on human populations can be better defined," Ferraro said. "Our findings may result in improved conservation programs and policies, and better impacts on the communities adjacent to these sites, locally and around the globe."