"Over the past decade, 'Payments for Environmental Services' (PES) have received a great deal of attention as a natural-resource management approach. We propose a revised definition and framework for PES implementation that focuses on the use of positive incentives as the philosophy behind PES and conditionality as the method for influencing behaviors. We note the importance of additionality of PES interventions to justify their value in a wider context. Finally, we highlight the need to understand the local institutional context in terms of the characteristics of buyers, sellers, and their relationship for implementation to be effective. Our framework acts as a platform to begin examining how the variety of options for structuring PES projects can be adapted to a range of existing institutional contexts."