Abstract for: The use of qualitative modeling to derive qualitative policy implications from structural aspects of a model – a practical case

This paper reports about and interprets a qualitative system dynamics effort undertaken in the context of urban transportation systems in Latin America. In this case, the available time was too short to attempt model quantification and simulation. A stock-and-flow diagram with units of measure and tentative equations was developed and its structure analyzed. The analysis of the reachability between variables and of the shortest independent loopset around one centrally important variable have allowed to elaborate a series of qualitative indications and recommendations. The case is used to argue that, if cautiously interpreted, a qualitative model can yield helpful insights.