Urban population has been growing consistently worldwide, with large metropolitan areas experiencing expansion phenomena both in terms of population and extension. Naturally, these processes did not occur homogeneously throughout the territories. Through the last decade, population in suburbs has largely increased while the population living in Central Business Districts has generally shrunk in many of the European and American cities. Portugal is not an exception and several cities have been largely affected by this phenomenon, suffering significant changes in their economic structure and characteristics, particularly through residences and jobs ?relocation? to the suburbs. Our main aim is to establish the theoretical design of a modelling framework to assess social, economic, energy and environmental impacts of changes in urban forms and commuting patterns in the regions studied. Accordingly, we will use a multi-regional input-output model which considers the areas defined as the Central Business District (Lisbon municipality), the suburbs (North Lisbon metropolitan area and Setubal Peninsula) and the ?Rest of the country?. The model will then be extended with satellite accounts regarding social, energy, environment and mobility issues, in order to assess the (direct, indirect and induced) multidimensional effects of commuting felt within each metropolitan region and the ones that leak to other regions. This model has as an innovative feature, the fact that it distinguishes the final consumption of three types of households: the ones which do not commute, the ones which commute to other regions, and the ones who are real estate owners. Finally, the model will comprise a commuting satellite account which will allow to deal with the impacts on income, employment, energy requirements and emissions among regions, as well as with resulting changes both in the consumption patterns and in the location/region where consumption actually takes place. This modelling framework should allow for the assessment of the multidimensional impacts resulting from several scenarios reproducing real and/or hypothetical changes in commuters? behaviour and in the policy measures, such as, e.g.: modifications in household location, changes in travelling patterns and commuting distances, external shocks in the economies of these regions, the delocalization of industries or headquarters between regions, the implementation of specific (local, regional or national) policy measures.
