- 學位論文
以GDP為中介變數探討所得分配不平等和環境因素對預期壽命的影響
Exploration of the Impact of Income Inequality and Environment on Life Expectancy with a Mediating Role of GDP
摘要
本研究收集從 2004 年到 2014 年間 23 個 OECD 成員國的總體資料，以 GDP 為中介變數探討預期壽命和所得分配不平等與環境因素的關係。為了提供實證研究的理論基礎，本研究採用 Preston 曲線、Kuznets 曲線和環境 Kuznets 曲線的理論。依據這三個理論的推論，本研究建立以 GDP 為中介變數的三個中介模型。第一是預期壽命和所得分配不平等之間的中介模型，第二是預期壽命和環境之間的中介模型，第三是預期壽命和所得分配不平等與環境的中介模型。為了進一步了解三個中介模型，本研究設計中介效果驗證流程。在驗證時，以 GINI 係數、所得前 5/1 人口佔比和日支出不超過 1.9 美元的貧困人口佔比為特定所得分配不平等的變數，以二氧化碳排放量、核能源的發電比率、天然氣的發電比率和水資源的發電比率為特定環境的變數。本研究結果顯示，儘管在預期壽命和各 7 個特定變數之間 GDP 中介的效果並不相同，但確定了 GDP 中介在預期壽命和各 7 個特定變數之間的關係，並推論 GDP 中介預期壽命和所得分配不平等與環境的關係。至於所得分配不平等，結果顯示特定所得分配不平等的各個變數對預期壽命不一定有負面影響。但依據實證的結果推論所得分配不平等對預期壽命的負相關大於正相關。至於環境，結果表示環境退化跟預期壽命之間有負相關。為了呼應三個曲線理論均以 GDP 為中介的結構，本文以嶄新的方法-GDP 為中介變數，進一步探討所得分配不平等和環境對預期壽命的影響。鑒於這些研究結果，希望可以獲得不同以往的關注。
並列摘要
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.