Lykke Sterll Christensen defends her PhD thesis at the Department of Economics

Candidate:

Lykke Sterll Christensen, Department of Economics, University of Copenhagen

Title:

Educational and Economic Inequality: Essays on School Access, Social Interactions, and Life Values

Supervisor:

• Mette Ejrnæs, Professor, Department of Economics, University of Copenhagen
  
  

Assessment Committee:

• Mette Gørtz, Professor, Department of Economics, University of Copenhagen
• Maria Humlum, Professor, Department of Economics, University of Aarhus
• Arnaud Chevalier, Professor, Department of Economics, Royal Holloway University of London

Summary:

This dissertation explores how institutional rules, individual traits, and family dynamics in childhood or youth influence outcomes in the short-run and, in one case, the long-run. Although the dissertation consists of four self-contained chapters, they are somewhat related by the population of study being children or adolescents enrolled in primary or lower secondary school.

Chapter 1: Playing the System: Address Manipulation and Access to Schools

Co-authored with Andreas Bjerre-Nielsen, Mikkel Høst Gandil, and Hans Henrik Sievertsen

Strategic behavior is common in allocation systems, increasing the demand for market designs that ensure fairness and transparency. While prior research has focused on the manipulation of reported preferences, i.e. ranking of desired schools, we highlight a hitherto overlooked form of strategic behavior: manipulation of fixed eligibility traits. In this chapter, we study whether Danish high school applicants manipulate the allocation system by strategically changing their residence to one that is closer to their most preferred high school when eligibility is based on residential proximity. Using population-wide administrative data and two policy reforms, we identify causal effects of incentive changes on address manipulation. The first reform increased the incentive to change residence, leading to a sharp rise in strategic behavior, particularly among higher-income families and applicants to oversubscribed schools. The second reform introduced verification requirements, substantially reducing manipulation and indicating that many address changes were likely not genuine. We show that such manipulation displaces non-manipulating applicants into schools with lower peer quality, potentially harming their academic environment. By simulating counterfactual admissions, we demonstrate that trait manipulation can have larger distributional consequences than traditional preference misreporting. Survey evidence confirms that applicants are aware of and willing to engage in this form of manipulation when incentives align and enforcement is weak. Our findings emphasize the need for market designs that anticipate and mitigate manipulation of eligibility traits, extending the focus beyond preference reporting.

Chapter 2: Perceived Self-Efficacy and School Starting Age

Starting school at an older age has been shown to improve early cognitive test performance, but subsequent research suggests these benefits largely reflect age-at-test effects rather than lasting cognitive gains. This calls into question whether school starting age (SSA) can explain long-term outcomes such as mental health, adult health, or educational attainment. In this chapter, I propose that perceived self-efficacy (PSE), a non-cognitive skill reflecting an individual’s belief in their capacity to overcome challenges, may be a key mechanism linking SSA to later-life outcomes. Using rich longitudinal survey data on Danish schoolchildren combined with administrative records, I estimate the causal effect of SSA on PSE through a fuzzy regression discontinuity design that exploits school entry rules based on birthdate. I find that starting school one year older significantly increases students’ perceived self-efficacy, with effects persisting throughout the school years. These results are particularly robust among children in grades 4–9, suggesting lasting psychological impacts beyond the early school years. To assess external validity, I examine heterogeneity across compliance types and find that treatment effects are localized: “never takers” tend to have higher baseline PSE, while “always takers” may suffer from behavioral challengeds that distinguish them from compliers. Nevertheless, the effects are relevant to a sizable population group. Additional analyses suggest that academic feedback and peer comparisons may partially mediate the relationship between SSA and PSE, particularly among older students. Based on these findings, teachers and schools could consider providing students with age-adjusted feedback on their academic test performance.

Chapter 3: Bullying and Birth Order

Co-authored with Emil Chrisander

School bullying has serious, lasting impacts on children's mental health, academic performance, and social outcomes. Drawing on psychological research suggesting that early family dynamics shape children’s social behavior, this chapter investigates how sibling birth order affects the likelihood of being involved in school bullying, either as a victim, a perpetrator, or both. We link comprehensive longitudinal survey data on Danish schoolchildren to registry data, applying a within-family design to isolate birth order effects. Furthermore, as the literature on bullying suggests that not only individual characteristics matter for the risk of bully exposure, but also the social context, we also examine how the birth order composition of school cohorts moderates individual bullying risk. We find that secondborns are more likely to engage in bullying but less likely to be victimized, yet with their risk of victimization increasing if the share of firstborn peers increase. Effects are particularly pronounced among secondborn boys and closely spaced siblings. In an attempt to understand why secondborn siblings have a higher likelihood of bullying compared to their firstborn sibling, we broaden the characteristic of secondborn siblings by investigating differences in non-cognitive traits across birth order. We find that secondborn siblings have less favorable traits, making them more emotionally vulnerable and less socially integrated. Hence, our findings suggest that early family roles influence children's school behavior and that this behavior may act as a precursor for later-life antisocial behavior. 

Chapter 4: Life Values in Adolescence Predict Life Course Earnings and Inequality

Co-authored with Claus Thustrup Kreiner, Asbjørn Juul Petersen, Søren Leth-Petersen, and Malthe Hauschildt Veje

A large literature in social science studies the determinants of lifetime earnings and intergenerational inequality. Cognitive skills, educational attainment, and parental background are well-established predictors of labor market success, with more recent work highlighting the importance of non-cognitive traits such as personality and preferences. In this chapter, we examine an underexplored determinant which is adolescent life values. In particular, we study whether values like conservatism and gender traditionalism predict earnings across the entire working life. Using population-wide administrative data linked to a nationally representative Danish cohort surveyed at 18-19 years old, we track earnings over four decades while controlling for cognitive ability, parental background, and time preferences. We find that life values measured in late adolescence are strong predictors of long-term earnings, comparable in importance to established factors like parental SES and cognitive skills. Individuals who express more conservative values tend to experience lower lifetime earnings, suggesting that early value orientations influence career paths, educational decisions, and responsiveness to labor market change. Our findings suggest that life values may be an overlooked driver of inequality which raises important questions about the development and malleability of life values during adolescence.

An electronic copy of the dissertation can be requested here: lema@econ.ku.dk