Title: Understanding Segregation Change
Description: Racial residential and school segregation, while having declined in recent decades, are still pervasive in U.S. metropolitan areas. Given the consequences of segregation for individual life outcomes and its role in exacerbating inequalities in the U.S., it is of major importance to better understand the processes that shape segregation. The goal of this dissertation is to develop methods that allow us to better understand which social processes are producing increases and declines in segregation. The dissertation consists of five substantive chapters. In chapters two and four, I develop two decompositions methods that allow the decomposition of changes in segregation. The first decomposition method focuses on providing a mechanical solution to the problem of "margin dependency." Unlike alternative methods, this decomposition does not attempt to "purge'" the index from its margin dependency, but instead quantifies how much of a given change in segregation is due to changes in the margins, compared to structural changes.

Arguably, this method provides more information about changes in segregation than a simple trend analysis. The fourth chapter introduces a more flexible method of decomposition, which allows the researcher to specify decompositions that are guided by theoretical considerations. This decomposition method is based on the Shapley value, originally developed in game theory. This chapter also shows that the Shapley value decomposition has many applications outside of segregation studies. The remaining substantive chapters are applications demonstrating the usefulness of these decompositions to understand changes in segregation. The third chapter applies the marginal-structural decomposition to a topic usually not considered in segregation analysis: the study of school-to-work linkages. This coauthored paper compares the skill-formation systems of France and Germany. Stratification research has often made a distinction between two ideal-types: "qualificational spaces," exemplified by Germany with a focus on vocational education, and "organizational spaces," exemplified by France with a focus on general education.

Most studies that investigated this distinction did so by focusing only on the size of the vocational sector, not on whether graduates with a vocational degree actually link strongly to the labor market. Moreover, these studies often studied male workers only, ignoring potential gender diﬀerences in how school-to-work linkages are established. Our approach is instead to map the change in education-occupation linkage in France and Germany between 1970 and 2010, using the marginal-structural decomposition to distinguish between changes in rates (marginal changes) and changes in the structure of school-to-work linkages (structural changes). Surprisingly, we find that the German vocational system in 1970 was not, on average, substantially more eﬃcient in allocating graduates to specific occupations than the French system. This finding is a major departure from earlier results, and it shows that the diﬀerences between 1970’s France and Germany, on which the qualificational-organizational distinction is based, are smaller than previously assumed.

Partly, this is due to the fact that the female labor force was omitted from earlier analyses. We thus show that ignoring the female workforce has consequences for today’s conception of skill formation systems, particularly because a large share of educational expansion is caused by an increase in female enrollment in (higher) education. In the remaining two chapters, I apply the Shapley decomposition strategy to two long-standing interests of U.S. sociology: racial residential and racial school segregation. The fifth chapter, on racial residential segregation, studies changes in segregation from 1990-2010. This paper engages with a prominent concept in segregation studies, the idea of micro and macro segregation. Micro segregation refers to the small-scale neighborhood segregation within cities and suburbs, while macro segregation refers to segregation between larger geographical areas, such as cities, suburbs, and school districts. The paper first shows that, contrary to other results in literature, while micro segregation decreased, macro segregation remained at similar levels.

Second, the paper shows that declines in segregation are almost exclusively caused by the Black and Hispanic populations, which have increasingly moved to majority-White areas. The sixth chapter studies changes in between-district school segregation from 2009 to 2016, studying both the relationships between school district racial composition and school district performance, as quantified by average test scores. Also in this later period, declines in segregation are mostly driven by the Black and Hispanic populations. Additionally, the decomposition by school district performance shows that families of all racial groups move from badly-performing school districts to better-performing districts.