An Empirical Study on the Assessment Ratio and Equity of Official Housing Prices in a Small and Medium-Sized City

This study empirically examines the equity of officially assessed apartment prices in Naju City, a local mid-sized city in South Korea. Using apartment transaction prices from 2023, adjusted to the January 1, 2024 assessment date, the study evaluates horizontal equity (intraclass uniformity) and vertical equity (price-related equity) by applying ratio analysis such as coefficient of dispersion, coverage ratio, and price related differential (PRD), conventional regression models, and quantile regression. The results show that the overall assessment ratio in Naju City is lower than the level announced by the central government, while horizontal equity is generally acceptable; however, the ratio in Bitgaram-dong, a planned innovation city, differs from those of older urban areas. Although the PRD indicates acceptable average price-related equity, conventional regression results vary by model and do not provide a consistent interpretation of vertical equity. In contrast, quantile regression results reveal a consistent pattern of progressive vertical inequity across all regions and price quantiles, with stronger progressivity observed among higher-priced apartments. These findings highlight the need to evaluate assessment equity in local cities, and demonstrate the empirical advantage of employing quantile regression as a complementary tool for examining vertical inequity in property tax assessments.