Social and Ethnic School Mixing: More Equity Through Intelligent School Allocation

Speaker: Oliver Dlabac, Co-Authors: Adina Amrhein, Fabienne Hug Abstract: School catchment zones, as employed in countries abstaining from free school choice, tend to reproduce residential segregation in terms of the schools’ social and ethnic compositions. This is problematic, particularly for urban areas with strong immigration of disadvantaged population groups, since high shares of disadvantaged pupils have an independent effect on school performance on all pupils, in addition to individual factors. In this paper, we confirm earlier findings for Switzerland, showing that this composition effect is not linear, but that the tipping effect only applies to schools with more than 30-40 percent disadvantaged pupils (social status, foreign language, immigration background). This is politically relevant, since it shows that school mixing policies do not harm better situated children, as long the share of disadvantaged children remains below a certain threshold. In the main analysis, we confirm how catchment zones in the six largest Swiss cities almost perfectly reproduce residential segregation. Additionally, we develop an internationally unique algorithm for designing socially and ethnically more balanced school catchment zones, while keeping the school routes short and safe and the catchment zones contiguous. The analysis shows substantial mixing potential for many disadvantaged schools that is not being exploited by the school authorities. Our school mixing algorithm is currently being reviewed for implementation by two Swiss cities.