The study examines the horizontal inequities that possibly arise from the differential tax treatment between business income and wage & salary income. This study is analyzed by three aspects; (i) difference of effective tax rate between two income sou...
The study examines the horizontal inequities that possibly arise from the differential tax treatment between business income and wage & salary income. This study is analyzed by three aspects; (i) difference of effective tax rate between two income sources (ii) existence of horizontal inequity between these two sources (iii) some improvement on horizontal equity based on new tax laws in 1996. The data used in the study are collected randomly selected from taxpayers, who paid income taxes in 1995 and 1996, in Seoul, Pusan, and Kyong-nam areas. To define equal ability to pay, our samples are sorted by 10 groups in terms of tax base. A measure of horizontal equity is calculated by group with the coefficient of variation(CV) from effective tax rate as well as the coefficient of residual variation(CRV) from regression. The findings of this study are summarized as follows: i) The appropriate tax rate of the business income taxpayers is higher than that of wage & salary income taxpayers. This difference is even bigger in 1996 than in 1995. ii) Under equal - ability - to -pay assumption, the horizontal inequity exists between two income sources. This horizontal inequity is bigger in 1996 than in 1995. iii) The introduction of new tax laws in 1996 worsen the horizontal inequity between two income sources. All these results were significant except for the result of analysis between business income in 1995 and 1996. The CVs of the two income sources for 1995 and 1996 are statistically shown to be significant at 5% and 1% respectively while the CRVs of the two income sources for 1995 and 1996 are statistically found to be significant at 10% and 1% respectively. It is generally known that the tax burden of wage & salary income is heavier than that of business income. However, the study shows different results.