The thesis examines the relationship between income inequality and residential segregation in Swedish cities. In recent years, in Sweden, much attention has been given to the direction of causality from residential segregation to income inequality. Residential segregation is considered to lead to a differentiation of opportunities between neighbourhoods and, therefore, to be a contributing factor to or even a major cause of income inequality in cities. The thesis focuses on the opposite direction of causality, from income inequality to residential segregation. In fact, residential segregation can also be seen as the spatial manifestation of existing disparities in income distribution, since residential location choices are always (although not exclusively) made within a predetermined framework of economic constraints.

Specifically, two research questions are addressed in this thesis. What institutional factors, in the Swedish context, favour the transformation of the social divide between specific population subgroups into a spatial divide between those groups? To what extent and in what ways does income inequality contribute to the development of residential segregation in Swedish cities?

The first part of the thesis explains why Swedish cities are characterized by higher levels of residential segregation than cities of other countries characterized by higher levels of income inequality. The historical and comparative analyses developed in the first two studies indicate that it is not so much the magnitude of immigration that accounts for this difference between Swedish cities and their more unequal counterparts in other countries but, rather, the institutional factors influencing the modes of incorporation of immigrants into cities.

The second part of the thesis analyses how, in recent decades, the increase in income inequality has influenced residential segregation patterns in Malmö and in the three major Swedish metropolitan areas. The third and the fourth study show that, during the studied period, the widening of income disparities between neighbourhoods mirrored the general upward trend in income inequality in the population. The growth of the immigrant population contributed only slightly to this trend and income inequality was primarily driven by changes in the distribution of market incomes. During the late study period, however, income sorting processes have played a steadily more important role in contributing to economic residential segregation. Therefore, neighbourhood-based urban policies have not succeeded to reverse, or even just impede, the trend towards an increased spatial clustering of poverty and wealth in Swedish cities.