We implemented a decision experiment in the field with rural peasants in Colombia to test the effects of introducing then partially or totally removing Payments for Ecosystem Services (PES). We consider individual and collective payments and different rules for removal. We find that there is clearly no behavioral â€˜crowding-outâ€™ when a PES is created then ended. Even a simple pre-versus-post-PES comparison finds â€˜crowding inâ€™, if anything, with contributions higher after PES was removed than before PES was introduced. Comparing to a control, without PES, strengthens that conclusion. We discuss four possible mechanisms explaining these findings: recognition or gratitude; lack of negative emotions; pre-existing and persistent intrinsic motivations, and evocation of pro-environmental behavior.