This dissertation contains four empirical studies examining associations between economic resources and social participation among Swedish adolescents. All four studies draw data from a school-based survey covering a nationally representative sample of the 2010 cohort of Swedish eighth-grade students.

Study I examines associations between economic resources and school class friendships. A child-centred perspective on economic resources is used, combining self-reported measures of adolescents' own access to economic resources with disposable household income measured relative to other students in the same school. Friendships are assessed through sociometric data – students nominate their best friends in the school class. Results show that students with the lowest within-school household incomes and students who report to often miss out on activities due to a lack of economic resources receive on average fewer friendship nominations and are more likely to experience social isolation.

Study II considers associations between economic resources (own economic resources and relative household income) and adverse relationships with school class peers. Two forms of adverse relationships are assessed: the risk of bullying victimisation (self-reported) and peer rejection (measured through sociometric nominations). Students with the lowest within-school household incomes receive, on average, more rejection nominations but are not at higher risk of bullying victimisation. In contrast, students who often miss out on activities with peers due to a lack of economic resources both receive more rejection nominations and are at higher risk of bullying victimisation.

Study III extends the examination of peer rejection, assessing whether students who differ from classmates on some sociodemographic characteristic are more likely to experience peer rejection. Results show an association between household income and peer rejection, but the association is largely similar across classrooms of varying income levels. Moreover, the likelihood of a student to reject a specific classmate is unaffected by differences in household income. In addition, the study examines corresponding associations between peer rejection and other sociodemographic characteristics: immigration background, parental education, and gender.

Study IV turns the attention towards participation in extracurricular activities. Cross-country research shows that children from lower-income households are less likely to participate in such activities than are children from more affluent households. The study documents such a pattern among Swedish adolescents and examines the merits of different theoretical explanations. Panel data models are used to examine whether changes in household income are associated with changes in participation. Results show that income changes are not in general associated with changes in participation, but a weak association is found between changes in income and ceasing participation among adolescents in low-income households. Results are more consistent with theoretical explanations emphasising cultural differences and non-economic forms of resource constraints, than with explanations emphasising household economic constraints.