In the mean time, the government has constantly tried to meet the demand of the times like the restoration of advanced economic effectiveness fit for the economic growth and the achievement of economic democracy, and correct the frame of unbalanced tax system. As for the revision of tax system after 1988, it has enhanced to capture the taxable gain by business income in order to promote the liability equity in the earned income and business income. Also, it has tried to achieve the equity by the enlargement of the earned income deductions and the reduction of burden of tax. Nevertheless, most of labor income earners have felt the inequity in the equity of burden of tax, and it has caused the conflict among the social classes.
The objective of this study was to investigate it by the time series analysis to what extent there was horizontal equity effect in the burden of tax according to the revision of tax system, using the macro-level data.