Evaluating for Impact: Randomized Control Trials of Watershed Protection

Maria Teresa Vargas planning conservation activities with local Chiquitano authorities. (Photo: Natura Bolivia)

Maria Teresa Vargas (2005 Fellow) launched Bolivia’s Watershared program in 2003. From its small beginnings of six landowners in Los Negros, more than 12,000 families are now conserving more than a million acres of water producing forests, in exchange for water-user provided development projects such as honey and fruit production and improved irrigation systems. 

By 2010, Watershared appeared to hold great potential for replicable, scalable in-kind transfers in exchange for conservation with a range of positive impacts, including human health. Pilot research had described the basic model and identified farmers’ and community leaders’ motivations to participate, but a basic question remained. “Does Watershared actually have an impact?” Nigel Asquith (Kinship Conservation Fellows Program Director) turned to Kelsey Jack (Kinship Conservation Fellows faculty) to design an experiment to find out.

Bolivia’s Parapetí River, source of water for the Guaraní Nation and the forests of the Chaco (Photo: Natura Bolivia)

Experimental impact evaluation tools, such as randomized control trials (RCT), pioneered by Nobel-prize winning economists Abhijit Banerjee, Esther Duflo, and Michael Kremer have revolutionized the approach to alleviating global poverty. Evidence based interventions now entirely dominate the development field. The research designed by Nigel and Kelsey was one of the first in the environmental sector to use an RCT. A total of 129 communities in Bolivia’s Santa Cruz valleys were randomly allocated to treatment or control (i.e., offered Watershared agreements or not). After five years, participants had significantly changed their behavior, and were more likely to perceive positive trends in water quantity and forest condition, and had more positive perceptions about the economic benefits of forests and perceived that water quality was improving.

Watershared participants in southern Bolivia show the development projects they received – plastic tubes to improve their irrigation systems – and the conservation contracts they signed in exchange. (Photo: Natura Bolivia)

Randomized control trials provide the “gold standard” for impact evaluation. However, they are few and far between in the conservation world. Other than those in Bolivia, there is only one other RCT of a large-scale conservation project, undertaken in Uganda. Although RCTs are challenging to undertake, these evaluations show that rigorous analysis of long-term, large-scale conservation interventions is possible. Learning how to use such evaluation tools is critical if conservation practitioners are to demonstrate measurable and attributable impact.

Other researchers have used the Randomized Control Trial methodologies. A team from Northwestern University has undertaken a similar study in Uganda, to see if forest conservation can help reduce climate change.

Featured: Kinship Program Director Nigel Asquith and Faculty Kelsey Jack

Nigel Asquith serves as Kinship Conservation Fellows Program Director and also as President and Director of Strategy and Policy at Fundación Natura Bolivia. He has also worked at the Smithsonian Institution, the Center for International Forestry Research, Conservation International, and the World Bank. Nigel’s work is currently funded by the European Commission and the MacArthur Foundation, and he previously received grants from the National Science Foundation, the Rockefeller Foundation, the Blue Moon Fund, and the UK’s Department for International Development.

Kelsey Jack served on the Kinship Conservation Fellows faculty (2013, 2014) and currently is an Associate Professor of Environmental and Development Economics at the Bren School of Environmental Science and Management, University of California, Santa Barbara. She is also co-chair of the Environment and Energy sector at the Abdul Latif Jameel Poverty Action Lab at MIT and directs the Poverty Alleviation group at the Environmental Markets Lab at UCSB.