所得稅變動對勞動供給的影響：以台灣勞動市場的拉法曲線為例

The effect of the change of income tax on labor supply: A case of Taiwan labor market''s Laffer curve

郭彥廷(Yen-Ting Kuo)

指導教授 ： 單驥

國立中央大學/管理學院/產業經濟研究所/碩士(2012年)

摘要

經濟學中，在提到關於稅率與政府稅收之間的關係時，最常被提及的就是拉法曲線(Laffer Curve)。依拉法曲線所示，稅收及稅率之間存在著彼此消長的關係，稅收會雖然會隨著稅率的提高而提高，但畢竟這是有極限的，超過這極限後，稅收會隨著稅率的提高而下降，這種稅率與稅收的關係是政策及學理上常常提及的重要課題，而本研究試圖估計出台灣勞動所得的部份拉法曲線，藉此為例，用以暸解在台灣勞動所得的部份拉法曲線中，目前的所得稅稅率與其所得稅稅收之間，是否已達拉法曲線的最高點。
本研究採用2002年行政院主計處「人力運用調查」的資料，以家計單位為主，模擬出在不同所得稅稅率下每家戶其勞動所得所應繳交的所得稅稅額，進而估計出台灣的受薪者其勞動所得所對應的拉法曲線的位置。實證結果顯示，家庭勞動收入高低的不同，其面對所得稅稅率的變動會有不同的反應，政策上若提高所得稅稅率，會讓台灣家庭的勞動者增加工作意願，並會延長其工時，如此一來，此一工作意願的提升自然會使得其年收入隨之上升，而提高其應繳交稅額，當然，政府稅收也會因之增加。
基於上述實證結果，本研究建議，政府若為因應目前財政窘迫的問題，仍不宜以增
加所得稅稅率為主，而宜另以擴大稅基為主要的因應之策，政府不應只是專注於受薪階級的部分，對於許多「帳面上」看不到的所得來源及許多的地下經濟活動等，都應該有相對應及有效的配套措施，才能兼顧稅收的增加與賦稅的公平性。

關鍵字

拉法曲線 ； 勞動所得 ； 勞動供給曲線 ； 綜合所得稅

並列摘要

Laffer Curve examines the relationship between tax rate and tax revenue. It argued that there is a trade-off between income tax rate and income tax revenue. In general, tax revenue will increase as tax rate increase, but there is a limit, when tax rate overpass this limit, tax revenue will decease gradually. This relation is relevant in both policy making and academic study, and our study has examined Taiwan’s labor income in order to understand the possible relationship between labor income in Taiwan and its associated income tax rate. In addition,whether the current labor income tax rates in Taiwan have already reached their peaks in terms of Laffer Curve will also be examined.
The data we used in this study is from Manpower Utilization Survey of 2002, which is compiled by the Directorate-General of Budget, Accounting and Statistics, the Executive Yuan, R.O.C., we used household unit as the unit for our study, and then simulate income tax payment in different tax rates for every family so that we estimate Taiwan’s labor income tax rates around the current labor income level and their possible locations in Laffer Curve.
Our empirical results indicate that every family makes different reactions when they face the change of tax rates. In policy making, increasing income tax rate will make Taiwan’s family’s labors enhance their willingness to work, and expand their work hours so that their annual wage and income tax payment can be increased, government income tax revenue also can be increased accordingly.
In regard to this result, nevertheless, our study recommends that government shouldn’t increase income tax revenue by increasing their income tax rates, instead, the government should increase their income tax revenue by expanding the tax base. It is suggested in this study that the government shouldn`t focus its tax base on paid worker only, possible III underground economic actions such as night market and personal business should be unveiled and they can all added into tax base.

並列關鍵字

labor income ； labor supply curve ； Laffer Curve ； consolidated income tax

參考文獻

政府統計資料與網站

〔1〕 Hausman, J. A., 1985, “Taxes and labor supply”, Handbook of Public Economics, edited by Auerbach, A. J. and M. Feldstein, North Holland, vol.1,pp.213-263.

〔2〕 Mincer, J., and S. Polachek, 1974, “Family Investment in Human Capital:

〔3〕 Gayer, D., 1977, “The effects of wages, unearned income and taxes on the supply of labor”, International Economic Review, vol.18, no.1, pp.101-116.

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