Modelling land use, deforestation, and policy: a hybrid optimisation-heterogeneous agent model with application to the Bolivian Amazon

We introduce a hybrid simulation model (‘SimPachamama’) designed to explore the complex socio-environmen- tal trade-offs of alternative policy bundles and policy sequencing options for stemming deforestation and reduc- ing poverty in tropical countries. Designed and calibrated to the initial conditions of a small forest village in rural Bolivia, the model consists of: (a) an optimising agricultural household module of heterogeneous agents that make individually optimal land-use decisions based on factor endowments and market conditions; (b) an encompassing general equilibrium ‘shell’ module that endogenously determines wages and links the agricultural labour market and rural-urban migration rates; and (c) a novel user-controlled policy-maker module that allows the user to make ‘real time’ choices over a variety of public and environmental policies that in turn impact land use, welfare, and migration. Over a 20-year simulation period the results highlight trade-offs between reductions in deforestation and improvements in household welfare that can only be overcome either when international REDD payments are offered or when decentralized deforestation taxes are implemented. The sequencing of pol- icies plays a critical role in the determination of these results.