過去研究文獻在探討貧富差距問題時,大多在最小平方廻歸的架構下,研究影響所得邊際效果的「平均」現象,對於所得分配異質性方面的討論則相對較少。本研究採用分量廻歸方法,考慮特性和報酬率分配的差異,並進行擬真分解分析,探討家庭結構的角度與所得分配不均之間的關係。本研究並藉此以驗證大前研一所提出的『M型社會』現象是否存在於台灣。 本研究首先使用分量迴歸,利用「特定分量」的概念,針對尾端分配分析,分析自變數之分配特性,並將1980年與2005年的分量結果相互比較,以了解所得分配惡化的趨勢。之後,本研究再引用Machado and Mata(2005)的方法,將1980年及2005年的非條件所得分配作擬真分解分析,計算不同年度之間所得分配差異所造成的原因歸屬。 本研究的實證結果顯示,家戶特性變數對所得不均度有顯著影響,但在擬真分析方面的結果顯示,2005年的所得分配的不均度雖然較1980年的惡化,但並未明顯呈現如大前研一所謂的「M型」社會結構。
This paper investigates the relationship between income distribution, household income, and income inequality in Taiwan. As we know that most of the income distribution literature are estimated has focused on average treatment effects. In this paper, a regression strategy is applied in this paper. We propose and derive the asymptotic distribution of a quantile equivalent of the Oaxaca decomposition. We first estimate the whole conditional distribution by quantile regression. Second, we use the algorithm developed by Machado and Mata(2005) to examine the relative importance of differences in household income and differences in the returns to these characteristics in explaining both 1980 and 2005 Taiwan’s income differences at a point in time. The main conclusion in this regard is that there is strong empirical support for linking income distribution to household income. By contrast, there appears to be less empirical support for explanations based on the effects of that the structure of Taiwanese society has emerged into a “M-shape” distribution.