Agricultural policies and farm structures - agent-based simulation and application to EU-policy reform

The development of competitive and efficient agricultural structures has been one of the central goals of agricultural policy making in addition to ensuring a fair standard of living for farmers. To achieve these goals, the agricultural sector in most industrialised nations has long been the subject of government interven­tions. However, many agricultural policies have worked counteractively to these goals by creating distortions in the use of resources. Against this background, the emergence of new and innovative modelling methods such as agent- based models, in addition to ever-in­creasing computing capacities has offered new possibilities to model adjustment reactions and to quantify the impact of agri­cultural policies. This thesis takes up these new methodologies and applies them to the modelling and evaluation of agricultural policy impacts on regional struc­tural change. At the centre of the thesis is the development of the spatial and dynamic simula­tion model of regional agricultural structures AgriPoliS (Agricultural Policy Simulator). The core of AgriPoliS is the understanding of a regional agricultural structure as an agent-based system, i.e., a system of interacting heterogeneous agents. The thesis contributes to a deeper un­derstanding of struc­tural change dynamics and factors causing structural change. It is studied whether and to what extent policy changes can facilitate structural adjustment towards a more efficient and competitive agricultural structure.