In a paper recently published on majority-Muslim hate crimes, as well as the present paper on segregation in schools, I rely on descriptive quantitative mappings as a backdrop for qualitative research. In my presentation, I will focus on cross-over methodology but also present some key results. This paper examines ethnic segregation in schools as a case of political inaction, or non-decision making. Since non-decision making is about the paths not taken, its study requires a combination of careful factual observation with an ethnographic approach to the counterfactual policy analysis. To enable such analysis, the focus of this study is on Halifax, an English town presenting archetypal scenarios of ethnic segregation and mixing in schools and neighbourhoods. After presenting a descriptive “landscape” of ethnic segregation and mixing, the subsequent qualitative analysis offers insight into the inner workings of value-based and procedure-based non-decision making that have wider application, transcending any given locality and sphere of public policy.