| Summary: | 博士 === 中原大學 === 商學博士學位學程 === 107 === This research explored the relationships between life expectancy and two factors−income inequality and environment−with a mediating role of GDP, based on data from twenty-three OECD countries for 2004 through 2014. To provide empirical grounds for systematic research, the Preston curve, Kuznets curve and environmental Kuznets curve were employed. The research set three mediation relationships with a mediator of GDP: the relationship between life expectancy and income inequality, the relationship between life expectancy and environment, and the relationship between life expectancy and two factors: income inequality and environment. Specific variables were chosen for analysis: Three specific variables characterizing income inequality are GINI index, income share held by highest 20%, and poverty headcount ratio at $1.90 a day; four specific variables characterizing environment are CO2 emissions, electricity production from nuclear sources, electricity production from natural gas sources, and electricity production from hydroelectric sources. The research found that GDP clearly mediates the effects of the seven specific variables on life expectancy, although the magnitudes of the effects vary. By the same token, it is justifiable to assume that the relationship between life expectancy and the two factors−income inequality and environment−is mediated by GDP. As to income inequality, the findings have shown that all variables characterizing income inequality do not necessarily have a negative relationship with life expectancy. But accepting the findings at face value, the negative effects of income inequality on life expectancy outweigh the positive effects. As to environment, the findings have shown that environmental degradation has a negative effect on life expectancy. Based on three curve theories, the research outlined the structural connectivity mediated by GDP to impart a greater plausibility to the conclusion. This approach provides a new paradigm in understanding the effects of income inequality and environment on life expectancy.
|
|---|
