Drivers of PES effectiveness: Some evidence from a quantitative meta-analysis

International audience; Payments for Environmental or Ecosystem Services (PES) schemes have become a popular tool to addressenvironmental degradation and to promote sustainable management of ecosystem services. We use metaregressionanalysis on a sample of 110 individual studies to investigate the determinants of the environmentaleffectiveness, defined as the probability to increase environmental services (ES) provision, of about 149 PESschemesimplemented worldwide. We find that increased effectiveness of PES schemes is strongly associatedwith periodical third-party monitoring, generic reference design and to a lesser extent results-based payments.We further study the determinants of PES additionality, defined as direct changes in ES provision induced by thePES scheme, compared to a baseline without PES, on a smaller sample of 41 studies from which we could obtainthe necessary data. The results confirm the role of certain design variables, such as monitoring type, and raise apotential trade-off between enrolment and additionality in the assessment of PES effectiveness.