Heterogeneous and interactive effects of payments for ecosystem services on household income across Giant Panda Nature Reserves

Numerous Payments for Ecosystem Services (PES) programs have been implemented simultaneously around the world but their outcomes in the literature are not consistent and their interactive effects remain understudied. The Natural Forest Conservation Program (NFCP) and Grain to Green Program (GTGP) are two largest PES programs in the world, and many studies have evaluated their effects on household income. However, the identified effects often varied across different studies and the factors explaining this variation are poorly understood. This study used linear regression and geographic detector analysis, based on questionnaire survey data from 14 giant panda natural reserves (NRs) in southwestern China, to evaluate the effects of the NFCP and GTGP on household income and the factors which moderate these effects. The results revealed that the effects of two PES programs on household income were spatially heterogeneous and enhanced by each other and livelihood activities, suggesting a synergistic interaction between policies and livelihood activities, particularly tourism. This study also found that livelihoods activities (e.g., labor migration and tourism), household capital (i.e., house area and farmland area) and demographic factors (i.e., number of labor and non-labor members), exhibit spatial heterogeneity in their effects on household income across NRs. These findings underscore the importance of considering local socioeconomic conditions and the interaction between policy and socio-economic conditions in PES program design to achieve desired outcomes, providing insights for policymakers and practitioners worldwide.