Intergenerational Income Mobility by Province in Korea: An Analysis Using National Health Insurance Big Data

This study analyzes regional differences in intergenerational income mobility using National Health Insurance big data, aiming to understand the causes of the worsening public perception of opportunity inequality. Specifically, the study calculates relative income mobility through regression analysis of income percentile of parents' and children's, and absolute income mobility using the average income percentile of children from the bottom 25% of income households. Additionally, as a preliminary analysis to identify the causes of regional differences in income mobility, the study examines correlations between income mobility and regional characteristics such as income inequality, spatial segregation index. The analysis found that, at the national level, intergenerational income mobility showed little change over time, and there was not much difference based on the type of health insurance subscriber. In particular, the absolute level of relative income mobility was not very high. However, intergenerational income mobility by region was found to be particularly poor in large cities such as Seoul, Gyeonggi, Daegu, and Daejeon. Moreover, the correlation analysis with regional characteristics showed that regions with higher income inequality and greater spatial segregation tended to have lower relative income mobility. For absolute income mobility, similar trends were observed, but statistically, the findings were not significant.