政府債務對於經濟成長之群集分析

Abstract

近年來世界政府公債總額不斷攀升，引起許多經濟學家擔憂全球債務泡沫，使政府公債對於經濟成長的影響在近年引起全球高度關注，而實證文獻大多證實其兩者之間存在一非線性關係，不論其結論為何，大多傾向於支持高公債水準下會帶來負面經濟影響。 本研究以 2000 至 2014 年間 OECD 34 個樣本國家為觀測對象，利用資料分群方法探討公債比對經濟成長的影響，並讓數據說話找出其最適群集，過去研究較少用此方法進行討論，但跨國縱橫資料當中常存在異質性問題，故本研究採 Lin & Ng(2012)所提出，針對異質性資料所適用的分群方法，讓數據自己找出最適當分群。 研究結果顯示，OECD 國家當中，政府公債占 GDP 比值對於經濟成長的關係皆為負向。利用分群方法得出四組，其中有一組效果為 0，其餘皆為負向關係。研究結果顯示在已開發國家當中，政府公債上升已經無法刺激經濟。與近年諸多實證分析的結果相同。

The impact of increasing government debt on growth depends highly on its function and objective. Debt may improve welfare and enhance growth by stimulating consumption; however, an irresponsible increase in debt level may also destroy the foundation of an economy. Currently, most of the empirical literatures have proposed the existence of a nonlinear relationship between debt and economic growth: moreover, an extremely high level of debt to GDP ratio is suggested to be an undesirable factor for long-term development. This research applies clustering methods to investigate the link between government debt-to-GDP ratio and growth of real GDP per capita in 34 OECD countries over the period from 2000 to 2014. Different sorts of groups are categorized by Cluster Analysis. The empirical results reveal the negative relation between the government debt to GDP ratio and the economic growth in OECD countries: more specifically, three out of four groups categorized by clustering methods hold the negative relation while the impact of the remaining group is neutral. The research suggests that the increase in government bonds may not be a good way to stimulate the economy in developed countries: this implication conform with many recent researches on government debt.