債務法則與內生成長:小型開放經濟的分析

Abstract

本文以Turnovsky (1996)小型開放經濟的模型為基礎，建立一個具生產性政府支出的內生成長模型，分析不同債務法則在靜止均衡時對經濟成長與福利的影響。我們發現，在小型開放經濟體系下，限制政府僅能就生產性政府支出部分才可發債融通的債券黃金法則，有助於公共資本的累積與經濟成長，且公共投資赤字融通程度與經濟成長呈正相關。固定赤字法則的政府赤字-所得比有一上限，提高赤字-所得比僅會增加消費性政府支出，對於公共資本的累積與經濟成長無任何影響。社會福利水準與消費期初值及其他外生參數習習相關，藉由數值模擬方法可知，債券黃金法則的福利水準高於固定赤字法則。在政策意涵上，若政府欲提升經濟成長與福利水準，對於非生產性的政府支出應以稅收融通，而公共投資建設則可透過發行國內債券的方式向大眾融資。

Based on Turnovsky (1996), this paper constructs an open-economy endogenous growth model featuring productive public capital and public debt, and uses it to analyze the growth and welfare effects under two different debt rule regimes. Several findings emerge from the analysis. First, the golden rule of public finance that a government cannot borrow to finance non-productive expenditures is beneficial for public capital accumulation and economic growth. Second, under the regime of the golden rule of public finance, a higher extent of debt-financed public investment is associated with a higher balanced growth rate. Third, under the regime of the fixed deficit rule, a rise in the deficit-income ratio is impotent in affecting public capital accumulation and the balanced growth rate. Fourth, with plausible values of initial consumption and other parameters, the welfare level under the regime of the golden rule of public finance is higher than that under the regime of the fixed deficit rule. Fifth, both economic growth and the welfare level would be boosted if non-productive government expenditures are financed with tax revenues and public investment is financed through public debt.