Insufficient or excessive investment under sovereign default risk
研究了私人投资决策对主权债券价格和违约风险的影响，发现政府因政治经济因素导致的短视可能使投资过度，而标准外部性理论认为投资不足，基于西班牙数据的量化分析显示短视效应占主导。
Private agents do not internalize the impact of their investment decisions on the sovereign’s bond prices and default risk. Therefore, a standard externality argument implies that investment is insufficient and that a subsidy can improve welfare, if financed by non-distortionary means. We contrast this logic with a countervailing force. When the sovereign is impatient relative to households, plausibly due to political economy factors, it finds laissez-faire capital accumulation excessive and might prefer instead to tax it. We embed both mechanisms in a sovereign default model with decentralized capital investment, long-term public debt, and stochastic trend growth, calibrated to salient features of the Spanish economy. We find that the impatience channel dominates quantitatively, to such an extent that laissez-faire is preferable to the government’s ideal fiscal policy, based on households’ welfare.