소득 불공평성, 조세 누진성 및 소득 재분배

This paper analyzes two issues of corporate income tax data of listed firms in Korea published since 1990s. The first one is about the intersections of the Lorenz or tax curves. Sykes et al.(1987) demonstrate that intersections of Suits-related tax curves are implicated by intersections of Kakwani-related Lorenz curves. The second one is about the relationships between income inequality, tax system, tax progressivity, and redistributive effect of taxation using their summary measures, i.e., the Gini coefficient, the total tax rate, the Suits index, and the Reynolds-Smolensky index, respectively. According to the empirical result about the first issue, the tax curve crosses the proportionality line and the Lorenz curve for taxes crosses the Lorenz curve for income in 1993. Because of these intersections of curves, the Suits and Kakwani indices show the opposite signs. This implies the importance of checking whether the Lorenz or tax curves are intersecting. The empirical results about the second issue based on regression and path analyses are as follows. The Suits index is affected significantly by the total tax rate and affects significantly the Reynolds-Smolensky index. The signs of their coefficients are both positive. This means that tax progressivity is positively associated with the total tax rate and the redistributive effects of taxation are also positively associated with tax progressivity. According to path analysis, the Gini index indirectly affects the Reynolds-Smolensky index via the total tax rate and the Suits index though there were no direct effects on the Suits or Reynolds-Smolensky indices.