The MARSUPIA research project will comparatively analyze the impacts of land policies on farmers’ investment decisions. Two land units were selected: 1. The Ontario green belt is remarkable for its zoning which considerably reduces uncertainty regarding land property. 2. The InterSCOT from the Toulouse region where uncertainty regarding land property is relatively higher despite the control of SAFER. The method used was validated by the REA and the ethics committee of the University of Guelph, where research on the Ontario green belt was done. It is based on an initial qualitative analysis where farmers were interviewed so as to identify factors which could generate regularity in the farmer’s decision making system. After that, two econometric models were tested to highlight the results for each land units. The first model will measure the level of investment by quantifying it through a financial variable (in Canadian dollars for the Ontario green belt).