中文摘要
我们在包含扭曲性税收的随机 OLG 模型中分析公共债务规模的财政与福利影响。政府借款利率对债务发行的敏感性符合现实,且低于增长率。由于公共债务的便利收益、异质性收益风险和总体风险,风险利率则要高得多。尽管“免费午餐”式赤字可以减少税收扭曲,但在校准至美国经济的基准模型中,福利最大化债务(WMD)明显低于赤字最大化债务(DMD)。对事前福利的详细分解揭示了塑造 WMD 的各种力量,其中最重要的是正的风险分担效应与负的挤出效应。我们识别了养老金政策、风险溢价等关键驱动因素,并量化了它们对 WMD 与 DMD 的差异化影响。将模型扩展以纳入市场势力后,WMD 大幅下降。当模型纳入财富不平等时,富人偏好的债务水平远高于中产阶级。
Abstract
We analyze the fiscal and welfare implications of the size of public debt in stochastic OLG models with distortionary taxation. The government borrowing rate is realistically sensitive to debt issuance and lower than the growth rate. The risky rate is much higher due to convenience benefits of public debt, idiosyncratic return risk, and aggregate risk. Although free-lunch deficits can reduce tax distortions, welfare-maximizing debt (WMD) is considerably lower than deficit-maximizing debt (DMD) in our baseline model calibrated to the US economy. A detailed decomposition of ex ante welfare reveals the forces shaping WMD, the strongest being the positive risk-sharing effect and the negative crowding-out effect. We identify key drivers, such as pension policy or risk premia, and quantify their differential impact on WMD and DMD. Extending the model to account for market power substantially reduces WMD. When wealth inequality is included in the model, the rich favor much higher debt than the middle class.