The development of urban models has been prompted by the need for informed policy recommendations from urban planners and informed decisions by policymakers. The imperative to develop integrated urban models for developing countries is growing with the need to enhance rational decision-making processes in controlling and directing urban change. The
demand for urban models for developing countries is particularly great because of the large number of variables and required policy parameters, the complex relationships among them, and the long-term consequences of public decisions. A spatial microsimulation model called InformalSim has been developed for Metro Manila. The microsimulation model uniquely provides detailed household microdata and allows the identification of the so-called ‘informal households’. This paper presents the development of residential and employment location choice models as extensions to the existing microsimulation model. Finally, the paper presents the possible role of such models in the development of spatial planning and decision support tool for developing countries.