Over the past four decades, government debt as a fraction of GDP has been on an upward trajectory in advanced economies, approaching levels not reached since World War II. While normative macroeconomic theories can explain the increase in the level of debt in certain periods as a response to macroeconomic shocks, they cannot explain the broad-based long-run trend in debt accumulation. In contrast, political economy theories can explain the long-run trend as resulting from an aging population, rising political polarization, and rising electoral uncertainty across advanced economies. These theories emphasize the time-inconsistency in government policymaking, and thus the need for fiscal rules that restrict policymakers. Fiscal rules trade off commitment to not overspend and flexibility to react to shocks. This tradeoff guides design features of optimal rules, such as information dependence, enforcement, cross-country coordination, escape clauses, and instrument vs. target criteria.

中文翻译：

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政府债务上升：数十年趋势的成因与解决方案

在过去的四十年中，发达经济体的政府债务占GDP的比例一直在上升，接近二战以来的最高水平。规范的宏观经济理论可以解释某些时期内债务水平的增加，以应对宏观经济冲击，但它们不能解释债务积累的基础广泛的长期趋势。相比之下，政治经济学理论可以解释长期趋势，这是人口老龄化，政治两极分化以及发达经济体选举不确定性上升的结果。这些理论强调了政府决策中的时间不一致，因此需要限制政策制定者的财政规则。财政规则要权衡不超支的承诺和对冲击做出反应的灵活性。