On Friday, March 6, Klara Gurzo will defend her doctoral thesis in public health sciences at Stockholm University. The dissertation examines how income and income mobility affect health over the life course and across generations in Sweden.
Time: 13:00-16:00
Location: ALB Auditorium 2, Albano
Opponent: Professor George Ploubidis, Department of Social Science, University College London
Location: ALB Auditorium 2, Albano
Opponent: Professor George Ploubidis, Department of Social Science, University College London
About Klara’s thesis
This thesis aims to investigate how income and income mobility shape health over the life course, highlighting the role of social and individual factors in these processes. It does so by, first, situating income-related health inequalities within broader historical and institutional change in Sweden. Second, it examines how intergenerational mobility is shaped not only by family resources but also by peer networks and personal attributes in childhood. Third, it analyses how childhood economic conditions translate into adult mortality and mental health, considering intermediary mechanisms and gender differences in these pathways.
Study I examined cohort differences in income-related inequalities in life expectancy before and after the establishment of the Swedish welfare state. Using nationwide register data, it compared individuals born in 1922–1926 and 1951–1955 and estimated temporary cohort life expectancy between ages 50 and 61. Results showed that although overall life expectancy increased, income inequalities widened, particularly among men. Life expectancy stagnated among men below the 25th income percentile in the later cohort. Among women, an individual income gradient emerged only in the later cohort, while household income gradients were evident earlier. Overall, the findings suggest that welfare state expansion did not proportionally benefit those with the lowest incomes, and relative income inequalities in longevity increased across cohorts.
Study II investigated whether childhood peer networks contribute to adult income attainment, beyond parental income. Using sociometric classroom friendship data from the Stockholm Birth Cohort, the study examined whether having at least one friend from a high-income family was associated with higher adult income. The results showed that privileged friendships were strongly associated with higher adult income, even after adjusting for parental income, cognitive ability, social skills, family structure, and education. The positive association was strongest for children from the lowest parental income quartile, suggesting that cross-class friendships may function as a channel of upward mobility. Cognitive ability and social skills were also important predictors of adult income. These findings highlight the role of peer-based social capital and early competencies in shaping economic mobility.
Study III analysed pathways linking childhood economic conditions to adult all-cause mortality. Using Cox proportional hazards models with follow-up between ages 52 and 71, the study examined whether childhood income influences mortality directly or indirectly through adolescent cognitive ability, social skills, and adult socioeconomic conditions. Parental income was modestly associated with adult mortality, but the association became non-significant after adjustment for cognitive ability and social skills. Cognitive ability remained strongly associated with mortality even after accounting for adult education, occupational class, and income, although its effect was substantially attenuated by educational attainment. No independent association between intergenerational income mobility and mortality was detected. The findings indicate that early-life cognitive resources and educational attainment play key roles in the pathway from childhood conditions to adult mortality.
Study IV examined whether intergenerational income mobility is associated with mental health in midlife, proxied by psychotropic drug dispensation between ages 52 and 66. Using diagonal reference models to separate origin, destination, and mobility effects, the study found a clear income gradient in mental health among individuals with stable income positions. Among women, mobility itself was not independently associated with psychotropic drug use after accounting for origin and destination income. Among men, however, downward mobility increased and upward mobility decreased the probability of psychotropic drug dispensation, net of origin and destination. These effects were modest but robust across specifications. The findings suggest that mobility-related stress mechanisms may be more relevant for men’s mental health.
Take home message
Income inequalities in health persist and, in some respects, widen even in a context characterized by an extensive welfare state. Economic advantages and disadvantages accumulate over the life course through interconnected mechanisms involving family background, peer networks, cognitive ability, education, and income trajectories. While income gradients in mortality and mental health are evident, mobility itself plays a more limited and context-dependent role, with modest and gender-specific effects. Overall, the thesis underscores that both structural conditions and individual-level attributes jointly shape the intergenerational reproduction of health and socioeconomic inequality.
Study II investigated whether childhood peer networks contribute to adult income attainment, beyond parental income. Using sociometric classroom friendship data from the Stockholm Birth Cohort, the study examined whether having at least one friend from a high-income family was associated with higher adult income. The results showed that privileged friendships were strongly associated with higher adult income, even after adjusting for parental income, cognitive ability, social skills, family structure, and education. The positive association was strongest for children from the lowest parental income quartile, suggesting that cross-class friendships may function as a channel of upward mobility. Cognitive ability and social skills were also important predictors of adult income. These findings highlight the role of peer-based social capital and early competencies in shaping economic mobility.
Study III analysed pathways linking childhood economic conditions to adult all-cause mortality. Using Cox proportional hazards models with follow-up between ages 52 and 71, the study examined whether childhood income influences mortality directly or indirectly through adolescent cognitive ability, social skills, and adult socioeconomic conditions. Parental income was modestly associated with adult mortality, but the association became non-significant after adjustment for cognitive ability and social skills. Cognitive ability remained strongly associated with mortality even after accounting for adult education, occupational class, and income, although its effect was substantially attenuated by educational attainment. No independent association between intergenerational income mobility and mortality was detected. The findings indicate that early-life cognitive resources and educational attainment play key roles in the pathway from childhood conditions to adult mortality.
Study IV examined whether intergenerational income mobility is associated with mental health in midlife, proxied by psychotropic drug dispensation between ages 52 and 66. Using diagonal reference models to separate origin, destination, and mobility effects, the study found a clear income gradient in mental health among individuals with stable income positions. Among women, mobility itself was not independently associated with psychotropic drug use after accounting for origin and destination income. Among men, however, downward mobility increased and upward mobility decreased the probability of psychotropic drug dispensation, net of origin and destination. These effects were modest but robust across specifications. The findings suggest that mobility-related stress mechanisms may be more relevant for men’s mental health.
Take home message
Income inequalities in health persist and, in some respects, widen even in a context characterized by an extensive welfare state. Economic advantages and disadvantages accumulate over the life course through interconnected mechanisms involving family background, peer networks, cognitive ability, education, and income trajectories. While income gradients in mortality and mental health are evident, mobility itself plays a more limited and context-dependent role, with modest and gender-specific effects. Overall, the thesis underscores that both structural conditions and individual-level attributes jointly shape the intergenerational reproduction of health and socioeconomic inequality.
The thesis can be downloaded at: SU DIVA portal