In Sweden, over 400,000 individuals are registered with debts for collection with the Swedish Enforcement Authority. The authority receives over one million applications for unpaid debts every year. In 2020, the number of applications increased by 26% compared to the same period the year before. Since then, the number of applications has fallen, but the median debt has instead increased by almost 20%. Despite the relatively high prevalence in the population, knowledge about the causes and consequences of over-indebtedness is low. The studies that do exist are largely based on interviews or survey responses and lack strategies to identify causal outcomes. Most studies focus on the relationship between over-indebtedness and health. The results show that over-indebted people are more likely to suffer from depression and chronic illness. The reason for the negative health effects is said to be the increased stress and stigma that over-indebtedness entails. In Sweden, the unique availability of individual data from the Swedish Enforcement Authority enables a systematic study of the effects of over-indebtedness. The research project aims to answer the following questions: (1) Why do individuals become over-indebted? (2) What are the social costs of the large number of over-indebted people in Sweden? By looking at individuals with debt and following their health and labor market outcomes, we can evaluate the negative effects of over-indebtedness. We will also look at whether over-indebtedness increases the risk of crime.