中文摘要
在包含异质性家庭与信贷摩擦的新凯恩斯模型中,我们表明,特质不确定性催生了一条额外的传导渠道,通过消费风险放大资产负债表政策的效应,使其成为锚定私人部门预期的关键工具。我们进一步表明,最优货币政策在常规工具与非常规工具之间存在明确分工:资产负债表政策应以横截面福利目标为导向,吸收具有分配相关性的变量(如私人债务)的波动,而常规利率政策则稳定总量目标并应对总量冲击,与代表性代理人基准情形一致。因此,针对债务去杠杆危机的最优应对是非常规的:相对于常规通胀目标制,零利率政策的持续时间更短而非更长,且不要求在有效下界处实施前置通胀。
Abstract
Within a New Keynesian model with heterogeneous households and credit frictions, we show that idiosyncratic uncertainty gives rise to an additional transmission channel that amplifies the effects of balance-sheet policies through consumption risk, making them a key tool for anchoring private-sector expectations. We further show that the optimal monetary policy features a clear division of labor between conventional and unconventional tools: balance-sheet policy should target cross-sectional welfare objectives, absorbing fluctuations in variables with distributional relevance such as private debt, whereas conventional interest-rate policy stabilizes aggregate targets and responds to aggregate shocks, as in the representative-agent benchmark. Thus, the optimal response to a debt-deleveraging crisis is unconventional: it entails a shorter, rather than longer, duration of zero-interest-rate policies relative to conventional inflation targeting, and does not require front-loaded inflation at the effective lower bound.