近年來，我國勞動所得份額逐漸下降，意味著經濟發展的同時，勞動階層所得未獲得增長，本研究欲以實證資料驗證該現象是否對我國所得分配造成影響。參考Chu et al. (2015) 使用我國財政部財稅資訊中心公告之綜合所得級距表並以Pareto插補法 (Pareto interpolation) 計算所得最高的10%、5%、1%、0.1%家戶自1981至2019年所得份額，藉以衡量所得分配之不均程度，並透過份額中的份額 (shares within shares)，以前述最高的1%與10%家戶、0.1%與1%家戶所得份額相除，來衡量不同所得階層之所得增長速度。以自迴歸分配落後 (autoregressive distributed lag, ARDL) 模型驗證非勞動所得份額與所得不均之關聯。模型中以人均GDP、社會福利支出、消費者物價指數 (Consumer Price Index, CPI)、貿易開放程度作為控制變數，另在模型中加入金融危機、2015年稅制改動之虛擬變數。除了虛擬變數外，其餘變數進行 ADF檢定 (Augmented Dickey-Fuller test) 及PP檢定 (Phillips-Perron test) 並取一階差分使其不具單根 (unit root)。
本研究結果發現，(一)、我國高所得者所得份額以及份額中的份額均呈現上升之趨勢，意味著所得階層越高，其所得增長速度越快。(二)、迴歸分析結果顯示前一期非勞動所得份額、貿易開放程度與CPI 對所得不均皆存在正向顯著效果；人均GDP、社會福利支出雖不顯著，但與所得不均呈現負向趨勢，虛擬變數金融危機與稅制改動皆對高所得者所得份額造成負面衝擊。綜合以上發現，本研究建議政府投入更多資源提升勞動競爭力以減緩勞動所得份額下降之趨勢，並重新審視過去數十年以來稅制調整之方針，避免惡化所得分配的租稅措施。

In recent years, the shares of labor income in Taiwan have decreased gradually. It appears that the income of salaried class hasn't grown accordingly while the economy is develop-ing. To realize if the phenomenon leads to income inequality, this research will cut in from a different point of view from the past. We use 1981-2019 tax data from Taiwan’s FIA (Fiscal Information Agency) of the Ministry of Finance in our country to estimate top income shares by Pareto interpolation, referred to Chu et al. (2015). Then, we take top income shares, such as 10%, 5%, 1%, and 0.1%, as variables of income inequality and use shares within shares, e.g., ratios income shares of top 1% to 10%, and of top 0.1% and 1%, to measure the growth rate in different income classes. To examine the relationship between non-labor income shares and income inequality, we adopt ARDL (autoregressive distributed lag) model, taking GDP per capita, social welfare expenditure, CPI (consump-tion price index), trade openness into account. We also set dummy variables to control the effects of financial crisis and tax policy changed in 2015 on income inequality. Be-fore regression analysis, we use ADF (Augmented Dickey-Fuller) test and PP (Phillips-Perron) test to ensure if the variables above except dummy variables have unit root or not. We use first-order difference to make variables have unit root become stationary.
The main findings are shown as follows. First, we find that top income household's shares and shares within shares are growing, which means the higher income classes have higher income growth. Second, the estimated results of ARDL model regression analysis shows that the trade openness, CPI and the lagged shares of non-labor income have positive and significant effects on income inequality. The financial crisis and tax policy changed in 2015 would reduce top income shares. Although the GDP per capita and social welfare expenditure are not significant, they have negative trends with income inequality. Based on the above findings, this study recommends that the government invest more resources to improve labor competitiveness to slow down the trend of declining labor income shares and reassess the tax policy adjusted in the past decades to avoid tax relief that worsen income distribution.

Adler, Martin and Kai Daniel Schmid (2012). “Factor shares and income inequality—empirical evidence from Germany 2002-2008.” German Socio-Economic Panel Study No.460.
Atkinson, A.B. (2005). “Top incomes in the UK over the 20th century.” Journal of the Royal Statistical Society: Series A (Statistics in Society) 168(2): 325-343.
Atkinson, A.B. (2007). “Measuring top incomes: methodological issues.” Top Incomes over the Twentieth Century: A Contrast between Continental European and English-speaking Countries. Edited by A.B. Atkinson and Thomas Piketty. New York: Oxford University Press: 18-42.
Atkinson, A.B. (2010). “Top incomes in a rapidly growing economy.” Top Incomes: A Global Perspective. Edited by A.B. Atkinson and Thomas Piketty. New York: Oxford University Press: 220-252.
Atkinson, A.B. (2014). “UK estimates of top income shares 2011-2012: Revised note on methods.” World Inequality Lab No. 201401.
Atkinson, A.B., Thomas Piketty and Emmanuel Saez (2011). “Top incomes in the long run of history.” Journal of Economic Literature 49(1): 3-71.
Bartels, Charlotte (2019). “Top incomes in Germany, 1871-2014.” The Journal of Economic History 79(3): 669-707.
Bengtsson, Erik and Daniel Waldenström (2018). “Capital shares and income inequality: Ev-idence from the long run.” The Journal of Economic History 78(3): 712-743.
Champernowne, David G. (1974). “A comparison of measures of inequality of income distri-bution.” The Economic Journal 84(336): 787-816.
Chancel, Lucas, Thomas Piketty, Emmanuel Saez and Gabriel Zucman (2021). “World Ine-quality Report 2022.” Edited by World Inequality Lab. Cambridge: Harvard University Press: 24-52.
Chiu, W. Henry and P. Madden (1998). “Burglary and income inequality.” Journal of Public Economics 69(1): 123-141.
Chu, C.Y., Teyu Chou and Sheng-Cheng Hu (2015). “Top incomes in Taiwan, 1977-2013.” World Inequality Lab No. 201506.
Dhawan-Biswal, Urvashi (2002). “Consumption and income inequality: The case of Atlantic Canada from 1969-1996.” Canadian Public Policy/Analyse de Politiques 28(4): 513-537.
Dickey, D.A. and Wayne A. Fuller (1979). “Distribution of the estimators for autoregressive time series with a unit root.” Journal of the American Statistical Association 74(366a): 427-431.
DiPietro, W.R. and Anoruo, Emmanuel (2005). "International trade and global income ine-quality." International Journal of Applied Economics 2(1): 121-131.
Fajnzylber, Pablo, Daniel Lederman and Norman Loayza (2002). “Inequality and violent crime.” The Journal of Law and Economics 45(1): 1-39.
Kim, Nak Nyeon and Jongil Kim (2015). “Top incomes in Korea, 1933-2010: Evidence from income tax statistics.” Hitotsubashi Journal of Economics: 1-19.
Leigh, Andrew (2007). “How closely do top income shares track other measures of inequali-ty?” The Economic Journal 117(524): 619-633.
Piketty, Thomas (2003). “Income inequality in France, 1901-1998.” Journal of Political Economy 111(5): 1004-1042.
Piketty, Thomas and Emmanuel Saez (2003). “Income inequality in the United States, 1913-1998.” The Quarterly Journal of Economics 118(1): 1-41.
Piketty, Thomas and Emmanuel Saez (2007 a). “How progressive is the U.S. Federal Tax System? A historical and international perspective.” Journal of Economic Perspectives 21: 3-24.
Piketty, Thomas and Emmanuel Saez (2007 b). “Income and wage inequality in the United States, 1913-2002.” Top Incomes over the Twentieth Century: A Contrast between Continen-tal European and English-speaking Countries. Edited by A.B. Atkinson and Thomas Piketty. New York: Oxford University Press: 141-225.
Piketty, Thomas and Nancy Qian (2009). “Income inequality and progressive income taxa-tion in China and India, 1986-2015.” American Economic Journal: Applied Economics 1(2): 53-63.
Piketty, Thomas (2014). “Capital in the Twenty-First Century.” Translated by Arthur Gold-hammer. Cambridge: Harvard University Press: 1-50.
Pickett, Kate E. and Richard G. Wilkinson (2015). “Income inequality and health: A causal review.” Social Science & Medicine 128: 316-326.
Roikonen, Petri (2021). “Income inequality in Finland, 1865-2019.” Scandinavian Economic History Review 2021: 1-18.
Said, S.E. and David A. Dickey (1984). “Testing for unit roots in autoregressive-moving av-erage models of unknown order.” Biometrika 71(3): 599-607.
Saez, Emmanuel and M.R. Veall (2005). “The evolution of high incomes in Northern Ameri-ca: Lessons from Canadian evidence.” American Economic Review 95(3): 831-849.
Schlenker, Eva and K.D. Schmid (2013). “Capital income shares and income inequality in the European Union.” Forschungszentrum Innovation und Dienstleistung (FZID) Discussion Paper No. 80-2013.
Stockhammer, Engelbert (2013). “Why have wage shares fallen? An analysis of the determi-nants of functional income distribution.” Wage-led Growth. Edited by International Labour Office (ILO). London: Palgrave Macmillan: 40-70.
Veall, M.R. (2012). “Top income shares in Canada: Recent trends and policy implications.” Canadian Journal of Economics/Revue Canadienne D'économique 45(4): 1247-1272.
Verme, Paolo (2011). “Life satisfaction and income inequality.” Review of Income and Wealth 57(1): 111-127.
Wood, A. (1998). “Globalisation and the rise in labour market inequalities.” The Economic Journal 108(450): 1463-1482.
朱敬一 (2014 a)，〈朱敬一教你一次讀懂《21世紀資本論》〉，《風傳媒》(2014/6/9)，網址: https://www.storm.mg/article/23089?page=1
朱敬一 (2014 b)，〈臺灣所得分配惡化隱藏不了〉，《獨立評論》(2014/6/23)，網址: https://opinion.cw.com.tw/blog/profile/261/article/1554
朱敬一 (2016)，〈朱敬一專欄：補上一堂課－所得分配不均的衡量〉，《風傳媒》(2016/3/20)，資料網址： https://www.storm.mg/article/90839?page=1
朱敬一、康廷嶽 (2015)，〈經濟轉型中的「社會不公平」〉，《臺灣經濟預測與政策》45(2): 1-22。
李碧涵、蕭全政 (2019)，〈新自由主義全球化時代勞動所得份額下降之探討〉，《國家發展研究》18(3): 1-44。
邱士豪、余俊憲、王怡心 (2016)，〈稅制改變對股利政策之影響－以可扣抵稅額減半為例〉，《財政部財稅研究》46(2): 31-51。
洪明皇、鄭文輝 (2013)，〈臺灣高所得者所得份額之變化：1977-2010〉，《調查研究-方法與應用》30: 47-95。
莊希豐、陳亞為 (2011)，〈貿易開放與所得不均：以門檻迴歸法分析〉，《經濟研究》47(2): 185-224。
陳孟甫、林弘文 (2007)，〈1994-2005年臺灣家庭所得不均度的分解與變化分析〉，《臺灣經濟論衡》5(6): 1-22。
陳建良 (2012)，〈臺灣家戶所得不均長期變化趨勢之分解〉，《臺灣經濟預測與政策》44(2): 1-44。
游麗君 (2012)，〈臺灣生產面要素所得份額之變動分析〉，《國家發展委員會研究報告》: 389-420。
劉碧珍 (2015) ，〈影響臺灣勞動份額變動因素之探討〉，《主計月刊》715(7): 30-38。
法務部全國法規資料庫，「所得稅法」，網址：
https://law.moj.gov.tw/lawclass/lawall.aspx?pcode=g0340003&msclkid=7fb036eec00311eca25df86b1068f5f1
行政院主計總處，「國民所得統計年報」，網址：
https://www.stat.gov.tw/ct.asp?xItem=48025&ctNode=3565&mp=4
行政院主計總處，「年度家庭收支調查」，網址：
https://www.stat.gov.tw/ct.asp?xItem=27900&ctNode=511&mp=4
財政部財稅資訊中心，「年度綜合所得稅申報核定統計專冊 」，網址：
https://www.fia.gov.tw/multiplehtml/43
財政部統計處，「財政統計年報」，網址：https://www.mof.gov.tw/singlehtml/285?cntId=64525
內政部戶政司全球資訊網，「年底人口數按性別、年齡及婚姻狀況分」，網址：https://www.ris.gov.tw/app/portal/346
AREMOS 經濟統計資料庫，網址：https://net.tedc.org.tw/?msclkid=006f308bc87511eca7cd1bdd5cbc31bb
行政院主計總處總體經濟資料庫，網址：
https://statdb.dgbas.gov.tw/pxweb/Dialog/statfile9L.asp