Colas Chervier is an economist at CIRAD (the French agricultural research and international cooperation organization working for the sustainable development of tropical and Mediterranean regions). He specializes in the evaluation of policies and interventions for natural resource conservation and sustainable management. He is specifically interested in how economic, fiscal and administrative incentives (e.g. payments for environmental services) can help change the behaviour of land users (such as farmers) and bureaucrats/authorities. He relies on counterfactual and qualitative methods for causal inference and the use of theories of change to analyze the design, the effectiveness and the conditions of effectiveness of such interventions. He is currently interested in applying these methods to the evaluation of landscape and jurisdictional approaches to zero deforestation.