Our general purpose is to analyze decisions related to mode choice and residential location, with a special emphasis on within-family decision process and on policy implications. Our approach extends the current literature by explicitly recognizing that the decisions of different family members are interrelated and we describe them as the outcome of a within-family bargaining process. On the one hand, this project will provide a new application field to family economics, and on the other hand, urban and transportation economics will benefit from economic literature on bargaining and collective decisions, largely ignored till now, with a few exceptions by some consortium members. In Part 1, we model spouses’ joint mode choice for commuting trips. The interaction is due to the fact that spouses may share a single car, or may carpool. As such, the choice of the car (or of who is driving it if it is shared) is described as the outcome of a bargaining process. In Part 2, we study residential location choices, which are the outcome of a subtle compromise when the two spouses work at different places, extending up to a three-stage nested Logit model. More precisely, we will model tenure choice, residential location choice and workplace choices, in the context of hierarchical nested models, including the (Pareto) weights of each spouse. The research combines stated preferences (using survey and experimental economics data), and revealed preferences (using census data for the Paris-Ile-de-France Region). In Part 3, we investigate the effect of public urban policies on household residential location choices by extending Part 2 models to investigate the effects of (1) capacity constraint (when prices do not clear the market and supply is lower than demand in some places); and (2) credit constraints on household tenure and location choices. Credit constraints either refrain households from buying some apartment or house, or induce them to move far enough from the city center (and often far from their job location) in order to find an affordable housing. These financial constraints are based on household income and other characteristics, and affect household joint residential decisions. The project is coordinated by University of Cergy-Pontoise (UCP), which has established a tradition in transportation and urban economics, and associates ENS-Cachan, with researchers specialized in discrete choice models and public policies, and Ecole Polytechnique, who plays a major role in the management of large data sources, and in data collection. This mix of resources and knowledge is crucial to attain the purpose of this interdisciplinary project. This collaborative project involving scholars in France, Europe, USA and Australia builds on the results of two previous projects coordinated scientifically by ENS-Cachan, for the first one and by UCP, for the second one. (1) In SustainCity, a collaborative PF7 European project (with 12 partners), a European Land Use and Transport Integrated (LUTI) model was developed and applied by UCP to Paris Region. (2) In the French Predit project MobMen, an interactive survey (MIMéTTIC, Mobilité Individuelle, mobilité des Ménages, Tarification des Transports Individuels et Collectifs) was administered. UCP elaborated an innovative protocol and collected individual data (4,000 respondents, including 1,000 couples). This unique dataset provides the information required to build mobility family decision models. Given the innovative dimension of this project, such data based was required for the development of realistic couple decision models. Other data will be used: The French General Population Census, and the data collected with on-line questionnaires and in experimental economics laboratories. The medium and long-term social and economic implications of several policies will be analyzed, such as: tolling, zoning, regulation, provision of infrastructure or provision of social housing.