A problem in the Dutch agriculture and horticulture is the gap between government actions and what individual farmers want. Policy measures are imposed on the agricultural sector as a whole but individual farmers make their own optimal decisions. To measure the effects of policy measures on the agricultural sector as a whole, all individual choices have to be aggregated. The main goal of this research is to measure and visualise the effects of policy measures on the agricultural sector as a whole. And because the combination of the Principal Agent Theory with cellular Automata is not very common another important goal here is to further develop this method of research. In this research an application in the horticulture will be worked out. This research combines micro economic simulation with the Principle Agent Theory and Cellular Automata to come to a model that: - explains the impact of policy measures on the agricultural sector, and - visualises the spatial impact of policy measures and the mutual impact of farmers on their decisions.