This project addresses the issue of social separatism and its consequences on the dynamics of inequality. This fundamental research is mostly related to Axis 3 “Spaces and Inequality Places” of the ANR program “Métamorphoses des sociétés: Inégalités-Inégalité”. It also addresses a number of issues of the thematical Axes 2, 4 and 5. We tackle these issues from an economic analysis perspective and develop a theoretical as well as an empirical analysis. Precisely, the research program is organized in 5 tasks, Tasks 1 and 2 being mainly theoretical and Tasks 3, 4, 5 corresponding to the empirical analysis. Task 1 opens the black box of social interactions by considering that the influence of group membership is mediated through social norms and networks. Task 2 tackles the issue of the impact of fiscal policy on social stratification. Task 3 is dedicated to the empirical study of the determinants of economic choices made by some segments of the population affected by segregation. We will use the survey Trajectoires et Origines (TeO) carried out jointly by INED and INSEE. Task 4 deals with the issue of student assignment mechanisms and their consequences on social mixing at school. It will proceed by simulating the effect of particular student assignment mechanisms on social mixing using data from Parisian primary schools. In Task 5, we plan to conduct laboratory experiments in order to identify some discrimination mechanisms and their consequences on social stratification. All these tasks will involve joint works. The team consists of 11 researchers. Finally, the team has not benefited from any external funding to develop this research.