再生性能源與總體經濟效率之提升

Abstract

本論文以資料包絡法分析再生性能源對四十五個經濟體在2001年到2002年技術效率的影響。在我們的DEA模型中，三項投入變數為勞動、資本存量及能源，實值GDP是唯一的產出變數。研究結果顯示，增加再生性能源的使用可以提高一個經濟體的技術效率。另一方面，增加傳統能源的投入卻會降低技術效率。OECD和非OECD經濟體相較，OECD經濟體之技術效率較高。在全體再生性能源之中，OECD經濟體使用之地熱、太陽能、潮汐及風力能源比例較非OECD經濟體高。然而非OECD經濟體所使用之再生性能源在總體能源供給的比例較高。如果固定傳統能源投入總量，我們可以藉著將傳統能源替代為再生性能源以提高技術效率。然而，若要進一步再提高技術效率，我們可以減少傳統能源及再生性能源的投入。文中傳統能源及再生性能源的節能目標係由DEA分析而來，我們計算經過總量調整後的再生性能源佔總能源投入的比率，發現並未比調整前高，由此可見，只要傳統能源及再生性能源的投入都能減少，未來各國並不需要強制設定再生性能源佔總能源的比例。只要兩種能源的投入都能減少，技術效率即能大幅提升。 為了證實增加再生性能源的使用確實能提高GDP，我們必須測試再生性能源的使用是否能提高資本形成及貿易淨出口。我們以路徑分析證實再生性能源的使用確實能提高資本形成。然而，再生性能源的增加和能源的進口卻成正向關係。並且再生性能源對貿易淨出口沒有顯著的影響。這些結果顯示再生性能源並沒有進口替代的效果且無法影響貿易淨出口。總而言之，我們證實再生性能源的使用確實能以提高資本形成的方式增加GDP，但是無法以提高貿易淨出口的方式增加GDP。

This article analyzes the effects of renewable energy on the technical efficiency of forty-five economies during the 2001-2002 period through data envelopment analysis (DEA). In our DEA model, labor, capital stock, and energy consumption are the three inputs and real GDP is the single output. Increasing the use of renewable energy improves an economy’s technical efficiency. Conversely, increasing the input of traditional energy decreases technical efficiency. Compared to non-OECD economies, OECD economies have higher technical efficiency and a higher share of geothermal, solar, tide, and wind fuels in renewable energy. However, non-OECD economies have a higher share of renewable energy in their total energy supply than OECD economies. If the total amount of traditional energy input is fixed, we could increase the technical efficiency of an economy by replacing traditional energy with renewable energy. However, to further increase technical efficiency, both the traditional energy input and renewable energy input should be reduced. The target traditional energy and renewable energy input are estimated by DEA. We calculate the new ratio of renewable energy in total energy after total adjustments and find that the new ratios of renewable energy after total adjustments for each economy are not greater than before adjustments. That means that if we could reduce both traditional energy input and renewable energy input, there is no need to set up national target of renewable energy ratio. The reduction of traditional energy input and renewable energy input could lead to great improvement in technical efficiency. To sum up, to confirm the relationship between the increase of renewables and the increase of GDP, we need to test whether renewables could increase capital formation or trade balance. We show that capital formation is positively influenced by renewables by path analysis. However, the relationship between renewables and energy imports is significantly positive. Further more, renewables do not have significant impact on trade balance. The results show that renewables do not have import substitution effect and could not influence trade balance. Thus, we confirm the positive relationship between renewable energy and GDP through the path of increasing capital formation but not the path of increasing trade balance.