Among OECD member countries, South Korea has a wide disparity in Gross Regional Domestic Product (GRDP) in absolute terms, with the gap widening further between 2015 and 2020. A similar analysis of per capita GRDP, which accounts for individual income distribution, ranks Korea higher―indicating a wider disparity― than the United States and Japan in terms of both absolute and relative terms. Overall, Korea faces significant disparities both between and within regions compared to its peers. Against this backdrop, this study empirically analyzes the current state and key drivers of the inter- and intra-regional disparities, providing policy insights for balanced regional development. It consists of two parts: (1) an examination of the impact of inter-regional disparities on population movement, and (2) an analysis of intra-regional income inequality.

Chapter 2 examines factors influencing representative indices for four key sectors―employment, education, housing infrastructure, and childcare―selected for their high relevance to the Korean context. The analysis covers 227 cities, districts, and counties across Korea from 2013 to 2022. This study empirically assesses how these four sectors influence total population (stock) and population inflow (flow) while considering mobility patterns by age group.

Findings show that better local conditions in employment and housing infrastructure contribute to growth in total population and population inflow. By age group, enhanced education and childcare services have a positive effect on attracting individuals in their 30s and 40s. In the Seoul Metropolitan Area, improvements in employment, education, housing, and childcare serve as primary drivers of population inflows. However, in non-metropolitan areas, even improvements across all four sectors do not significantly influence population inflows or mobility patterns across their administrative boundaries. Overall, the effects of sectoral improvements on population growth and mobility appear asymmetric between the Seoul Metropolitan Area and non-metropolitan areas. The stronger effects observed in the Seoul Metropolitan Area are likely attributable to differences in sectoral quality or a prevailing preference for the metropolitan area, where strengthening the key sectors in non-metropolitan areas alone may not be sufficient to drive residential relocation.

Based on the findings, the study presents the following policy recommendations for regional development. First, regional development strategies should adopt a coordinated, multi-sectoral investment approach, concurrently targeting dimensions like job creation, education, housing, and childcare, alongside a strategy to comprehensively enhance living conditions. To date, policy efforts have focused on single-sector investments, which have had limited effects on population inflows. Given the differing impacts on population inflows between metropolitan and non-metropolitan areas, narrowly focused investments alone are unlikely to serve as effective incentives for attracting people, highlighting broad-based investments as a vital policy tool for boosting regional appeal.

Second, strengthening cultural, educational, and social welfare infrastructure that reflects local characteristics is essential for improving residents' quality of life. Mobility patterns show that within non-metropolitan areas, movements mainly occur within the same cities and provinces, with limited inflows into other non-metropolitan areas. However, outflows to the metropolitan area increase when metropolitan conditions improve, suggesting the need to develop non-metropolitan areas into more viable and attractive living environments that can better compete with the metropolitan area in both quantity and quality.
Third, non-metropolitan areas need a sustainable, long-term regional development model led by local governments, together with a paradigm shift in the existing balanced regional development policy. Since qualitative improvements across all sectors take time, regional development strategies should move away from short-term population growth targets and prioritize long-term effectiveness based on regional strengths and weaknesses.

In conclusion, comprehensive improvements in sectors like employment, education, housing, and childcare through a population mobility-centered approach can help non-metropolitan areas to transform into more attractive places to live and work, complemented by tailored development strategies that reflect local characteristics.

Chapter 3 examines trends in income inequality at both national and regional levels in Korea. Using Gini coefficient decomposition analysis, the study assesses the extent to which inter- and intra-regional disparities contribute to overall income inequality. It further explores the relationship between city/provincial-level income inequality and per capita Gross Regional Domestic Product (GRDP) through a regression analysis covering 24 years (1998~2021). Additionally, the contribution of different income sources to national and regional income inequality is analyzed, with a focus on variations by age group of household heads, categorized as young (39 years and under), middle-aged (4064 years), and elderly (65 years and older).

The key findings on income inequality are as follows. First, decomposing the overall Gini coefficient into inter- and intra-regional components shows that inter-regional inequality has declined over time. In contrast, intra-regional inequality has remained relatively stable, making it a more significant factor in overall inequality. Analysis of the relationship between intra-regional income inequality and per capita GRDP at the city/provincial level based on such trends reveals an "N-shaped" pattern, where income inequality initially increases with economic growth, then decreases, and subsequently rises again. Additionally, higher average age of household heads, higher labor income across all age groups, and higher social insurance income among older adults are associated with lower income inequality. Notably, in non-metropolitan areas, the negative relationship between labor income and inequality is more pronounced.

Next, analysis of the contribution of different income sources to inequality indicates that reducing disparities across income categories―labor, real estate, other, transfer, social insurance, and financial―would be crucial for alleviating overall income inequality in the listed order. Over time, labor income inequality has worsened in the metropolitan area compared to non-metropolitan areas. Among young household heads, the contribution of labor income inequality to overall inequality was initially lower in the metropolitan area than in non-metropolitan areas, but this trend reversed around the mid-2010s and has remained higher since then. For older households, while no consistent pattern emerges, labor income inequality in non-metropolitan areas has been steadily increasing since the early 2000s.

Findings in Chapter 3 show that income inequality during economic growth follows an N-shaped pattern rather than an inverted U-shaped pattern, indicating that rising income inequality is not merely a transitional phase of economic growth but may persist or even intensify depending on various socioeconomic conditions. Therefore, continual monitoring of income inequality trends and efforts to mitigate its deepening should be integral to national and regional development strategies. Moreover, based on the analysis of income source contributions to inequality, reducing labor income disparities among young people is critical for alleviating overall income inequality in the metropolitan area. In non-metropolitan areas, the increasing labor income inequality among older adults requires particular attention. While labor income constitutes a relatively small share of their total income, its growing inequality could have a significant impact, especially given the faster population aging in non-metropolitan areas. This underscores the need to strengthen stable labor income sources for older adults in non-metropolitan regions.

Preface
Summary

Chapter 1. Introduction
　References

Chapter 2. Impact of Regional Disparities on Population Movement
　Section 1. Background and Purpose of the Study
　Section 2. Literature Review
　Section 3. Derivation of Key Sectoral Indices by Region
　Section 4. Patterns of Inequality Across Regions and Sectors
　Section 5. Empirical Analysis
　Section 6. Conclusion and Policy Implications
　References

Chapter 3. Patterns of Regional Income Inequality and Contribution by Income Source
　Section 1. Background and Purpose of the Study
　Section 2. Literature Review
　Section 3. Analytical Framework
　Section 4. Data Description
　Section 5. Analysis Results
　Section 6. Synthesis and Policy Implications
　References

Appendix
Abstract