The Regional Multi-Agent Simulator (RegMAS): an open-source spatially explicit model to assess the impact of agricultural policies.

Regional Multi-Agent Simulator (RegMAS) is an open-source spatially explicit multi-agent model frame- work specifically designed for long-term simulations of the effects of policies on agricultural systems. Using iterated conventional optimisation problems as agents’ behavioural rules, it allows for a bidirec- tional integration between geophysical and social models where spatially distributed characteristics are taken into account in the programming problem of the optimising agents. With RegMAS it is possible to simulate the local specific response to a given policy (or scenario), where policies, together with macro- and regional characteristics, are read into the program in specially formatted spreadsheets and standard GIS files. The paper presents the model logic and structure and describes its functioning by applying it to a case- study, where RegMAS results are compared with conventional agent-based modelling to demonstrate the advantages of spatial explicitness. The simulation refers to the impact of the recent “Health Check” of the CAP on farm structures, income and land use in a hilly area of a central Italian region (Marche).