Income Inequality among Taiwan Farm and Non-farm Households: Accounting for Income Sources and Household Size

所得不均的議題在經濟學領域中是長久以來持續被討論的問題，尤其是近年來在全球經濟環境變化下，各界對於所得不均問題的惡化越趨重視，而在貿易自由化的衝擊與面臨轉型的壓力下，台灣的農家所得與福利分配究竟受到何種影響更是需要被關注的議題。本研究採用主計處1979-2008年之家庭收支調查資料，利用多種指標衡量不均度，並將家庭人口規模納入考量，探討人口不均度與各種細項所得對於農家所得不均的影響。本研究同時經由與非農部門之比較以了解農家在所得不均上與其他家戶的差異，因此對於非農家戶之所得不均現象亦有深入探究。 本研究之實證結果顯示，農家所得不均度主要受到高所得農家之影響，且在1993年前呈現上升之趨勢，而在此期間人口規模之變動確實影響所得不均度之變化，但整體而言農家所得不均度的改變仍主要來自人均所得本身的變動。在所得來源的拆解上，農家之農業與非農業所得皆會擴大不均之程度，政府補貼則如預期有顯著縮小不均度之效果。在非農家戶中，所得不均度在均等化前呈現持續上升的趨勢，但在均等化之後，上升的幅度減緩許多；不同於農家，主要影響非農家所得不均度的族群乃是低所得家戶，且人口規模在研究資料期間都有增加不均度的效果。 無論在農家或非農家戶中，不同教育水準與年齡族群間之不均度的差異在均等化後並不顯著，顯示低教育水準與高齡等弱勢族群在福利分配上的問題或許不如未均等化指標顯示之嚴重。 Economists have long recognized the issue of income inequality. With globalization and recent changes in economic environment, this issue has become increasingly serious. In the case of Taiwan’s agricultural sector, it has been under the pressures of trade liberalization and agricultural reforms in recent decades. How the status quo may impact the welfare and income distribution of farm households needs to be examined. Using the data of the Survey of Family Income and Expenditure in Taiwan Area of Republic of China from 1979 to 2008, the income inequality in farm households was assessed by calculating various indexes, comparing inequality between different groups of households, and using the equivalence scale to take the household size into consideration. This study also applied two inequality decomposition techniques to quantify the contributions of the household size and income sources. In the mean-time, this study evaluated the income inequality in non-farm households, and investigated the differences between farm and non-farm households. The empirical results are summarized as follows. First, the income inequality in farm households was generally lower than that in the non-farm households after the incomes were adjusted according to an equivalence scale, and mainly influenced by high-income households. Second, although the household size raised the income inequality among farm households before 1993, the inequality in income was mostly affected by income per capita. Third, government transfer helped reduce the total income inequality in both the farm and non-farm households, whereas the farm and non-farm incomes both aggravated the income inequality. Different from the inequality of the farm households, the inequality among non-farm households was mainly affected by low-income households, and kept rising during 1979-2008. Also, it was continuously influenced by the household size. This study also found education and age of household heads did not show significance influence in household income inequality after the income were adjusted using an equivalence scale, suggesting that the problem of welfare distribution in the households with lower-education and elder household heads was not as serious as revealed by the unadjusted inequality indexes