AI 中文总结
该研究以美国货币联盟为对象，结合区域军事建设的因果估计与多区域量化模型，发现风险分担可直接平滑消费、间接稳定收入，当前水平将州级消费波动率降至四分之一，一体化收益大于传统衡量结果。
AI 中文摘要
美国是一个货币联盟，拥有迁移、财政转移支付、收入多元化、信贷市场等多种风险分担机制，可缓冲消费免受地方收入波动影响。研究表明，风险分担不仅能直接平滑消费，还可通过抑制地方乘数间接稳定收入。结合区域军事建设的因果估计与多区域量化模型，发现当前风险分担水平将美国州级消费波动率降低至原来的四分之一，且收入的间接稳定贡献了近一半的效果，这意味着一体化带来的收益远大于传统衡量指标所显示的水平。
英文摘要
The United States is a currency union where multiple risk-sharing mechanisms--- migration, fiscal transfers, income diversification and credit markets---buffer consumption from local income fluctuations. We show that risk sharing not only directly smooths consumption but also indirectly stabilizes income by dampening the local multiplier. Combining causal estimates from regional military buildups with a multi-region quantitative model, we find that current levels of risk-sharing cut state-level consumption volatility by a factor of four. Crucially, the indirect stabilization of income accounts for nearly half of this effect, implying substantially larger benefits from integration than conventional measures suggest.
