Additionality in Theoretical von Thünenian Models of Deforestation and Conservation Payments

Simple theoretical von Thünenian models of deforestation and agricultural expansion have been extensively studied in the literature but have not yet been adapted to reflect contemporary conservation paradigms, such as the emergence of REDD+ (Reducing Emissions from Deforestation and Forest Degradation) initiatives, related payments for forest conservation, and payments for ecosystem services (PES) more broadly. We revisit Angelsen’s 1999 seminal adaptation of the 1826 von Thünenian model of deforestation and agricultural expansion and propose a “toy model” to incorporate the potential revenues from conservation payments and build on the concept of additionality in the payments for environmental services literature. As theorized, our extended model illustrates how such payments are more effective when they approach the profit margins of geographically peripherical crops that replace the forest. Moreover, it illustrates how conservation payments influence the agricultural frontier while quantifying the avoided deforestation area.