Social segregation among colleges.

Summary Social segregation among French middle schools is significant: in 2015, one-tenth of middle schools enrolled less than 14.6 percent of students from disadvantaged social backgrounds and one-tenth enrolled more than 62.7 percent. This segregation, measured by the standardized entropy index, can be broken down into three parts. The first corresponds to the differences in social composition between the public and private sectors, which vary greatly from one academy to another. The next two parts correspond to the segregation within the colleges in each sector. In the vast majority of académies, the segregation between private collèges is greater than that between public collèges. On a national scale, the disparities between collèges have remained stable since 2003. On the one hand, segregation has decreased among public sector colleges. On the other hand, the gap in social composition between the public and private sectors has increased. Social segregation between colleges also reflects urban segregation. Particularly in large urban areas, students from disadvantaged backgrounds are over-represented in certain residential areas. In public secondary schools, assignment is based on geographical proximity, and the degree of segregation is partly due to this urban concentration of disadvantaged students. Nevertheless, other local dynamics are also present. The local Moran indices make it possible to compare the social composition of a college with that of the surrounding colleges. Four types of middle schools are thus defined, depending on whether the middle school has a higher or lower proportion of students from disadvantaged backgrounds than the academy as a whole, and whether the surrounding middle schools are also, on average, more advantaged or disadvantaged. Comparing this typology with the distribution of disadvantaged students in the region makes it possible to identify middle schools whose social composition is at odds with their environment. In Seine-Saint-Denis in particular, the social composition of the private lower secondary schools, which is rather advantaged, differs from that of the surrounding schools.