Household income heterogeneity across employment type and sub‐region: Evidence from Seoul and Busan, 2018–2022

Abstract This study examines household income heterogeneity across employment types, sub‐regions, and income quantiles in Seoul and Busan. South Korea's two largest metropolitan cities have followed contrasting demographic and economic trajectories. Using the Seoul and Busan Welfare Condition Surveys, unconditional quantile regressions examine employment‐related and sub‐regional income differences in 2018 and 2022. Bootstrap‐based coefficient‐difference tests assess changes between the two survey years. The results reveal distinct distributional patterns. In Seoul, significant changes were observed in several sub‐regional income differences relative to the Central area, whereas in Busan, significant changes were concentrated in employment‐related income differences, particularly among temporary employees in sales and service occupations. Income measures including and excluding public transfers yield broadly similar patterns. In both cities, income increased significantly at the 75th percentile but not at the 25th percentile. Overall, the findings demonstrate substantial employment‐related, spatial and distributional heterogeneity and highlight the value of examining within‐city and distributional variation beyond metropolitan averages.