台灣各縣市所得分配不均對社會福利支出的影響

Abstract

在理論上，所得分配不均度對社會福利的影響，究竟是正向影響，亦或是負向影響，一直沒有定論。政治經濟文獻顯示，所得分配不均度對社會福利支出的影響為正向，乃是因為中位數投票理論。然而，許多文獻卻指出由於資本市場不完美，所得分配對社會福利支出之影響為負向。本研究使用台灣1994-2006年，7個市以及16個縣的實證資料，來探究此議題。應變數為各縣市社會福利支出佔總支出的比例，而所得分配不均度則以各縣市吉尼係數來衡量。本研究採用二階段最小平方模型，而第一階段模型所估計出的吉尼係數，則為第二階段模型中的自變數之一。本研究實證結果支持資本市場不完美假設，亦即所得分配不均度對社會福利支出的影響為負向。

Theoretical arguments on the impact of income inequality on social welfare spending are inconclusive. The political economy literature says that income inequality has a positive impact on social welfare spending because of the median voter preferences. However, several literatures argue that the income inequality has a negative impact on social welfare spending due to capital market imperfections. This study examines this issue empirically by using county-and-city panel data of 16 counties and 7 cities of Taiwan from 1994 to 2006. The dependent variable is defined as the social welfare spending in percent of total local expenditure, and the income inequality is measured by regional Gini index. The study adopts two-stage least squares model (2SLS). The model in the first stage is a modification of Huang and Liu (2005). And the Gini index predicted by the first stage is used as the key independent variable in the second stage model. The 2SLS model in this study supports the capital market imperfections hypothesis. That is, more unequal societies might spend less on social spending