所得稅制、不均與經濟成長

THE INCOME TAX SYSTEM, INEQUALITY AND ECONOMIC GROWTH

本文結合Turnovsky（1990）與García-Peñalosa and Turnovsky（2006）的模型，同時納入兩稅合一制度，藉以分析在獨立課稅制與兩稅合一制之下，租稅政策對就業、成長與不均的影響，並且檢視成長與不均的關係。給定合理的參數下，研究結果發現，不管是獨立課稅制或兩稅合一制，個人所得稅降低可增加就業與經濟成長，降低財富與所得不均度，成長與不均為負相關。個人所得稅降低，兩稅合一制有較大的就業、成長、不均效果。其次，不管是獨立課稅制或兩稅合一制，營利事業所得稅降低可增加就業與經濟成長，提高財富與所得不均度，成長與不均為正相關。營利事業所得稅降低，獨立課稅制有較大的就業、成長、不均效果。最後，不管是獨立課稅制或兩稅合一制，個人免稅額提高對就業與經濟成長無影響，可降低財富與所得不均度，成長與不均為無相關。個人免稅額提高在兩稅合一制有較大的不均效果。

By introducing an independent income tax system and an integrated income tax system into an endogenous growth model, this study investigates the effects of tax policy on employment, economic growth and inequality. For reasonable parameters, this paper finds that reducing individual income taxes can increase employment and economic growth, but decrease wealth and income inequality, in both tax systems. There is a negative relationship between growth and inequality. The effects of employment, growth and inequality are large in the integrated income tax system. In addition, decreasing corporate income taxes can increase employment, economic growth, wealth inequality and income inequality in both tax systems. The relationship between growth and inequality is positive. The effects of employment, growth and inequality are large in the independent income tax system. Finally, an increase in the level of tax exemption results in no employment and growth effects, yet it decreases wealth and income inequality in both tax systems. An increase in level of tax exemption leads to a larger effect on inequality in the integrated income tax system.