Review of Economic Studies · 2024 · [{"name": "Florin Bilbiie", "affiliation": ["Université Paris 1 Panthéon-Sorbonne"]}]
中文摘要
THANK 是一个易于处理的异质性主体新凯恩斯模型，能够以解析方式刻画定量 HANK 模型的核心微观异质性渠道：周期性不平等与风险；自我保险、预防性储蓄以及现实的跨期边际消费倾向。本文用该模型阐明 HANK 模型的关键传导机制与动态性质。逆周期不平等会放大总需求，并使泰勒规则下的决定性条件更为严格；但解决前瞻性指引难题需要顺周期不平等——这构成一个两难困境。解决方案包括将不平等与一个独立的风险渠道相结合，使二者的周期性相互补偿；本文提供证据表明，在最近两次衰退（大衰退与新冠疫情衰退）中，可支配收入不平等是顺周期的，而风险是逆周期的。替代性政策规则也能解决这一两难困境，例如价格水平目标制，或者在包含流动性的模型版本中设定名义公共债务。具有异质性的最优政策包含一种新的不平等稳定动机，从而产生更高的通胀波动；但只要目标有效均衡不包含不平等，该政策就不受风险影响。
Abstract
Abstract THANK is a tractable heterogeneous-agent New-Keynesian model that captures analytically core micro-heterogeneity channels of quantitative-HANK: cyclical inequality and risk; self-insurance, precautionary saving, and realistic intertemporal marginal propensities to consume. I use it to elucidate key transmission mechanisms and dynamic properties of HANK models. Countercyclical inequality yields aggregate-demand amplification and makes determinacy with Taylor rules more stringent; but solving the forward guidance puzzle requires procyclical inequality: a Catch-22. Solutions include combining inequality with a distinct risk channel, with compensating cyclicalities; I provide evidence that disposable income inequality was procyclical in the last two, Great and COVID recessions, while risk is countercyclical. Alternative policy rules also solve the Catch-22, e.g. price-level-targeting or, in the model version with liquidity, setting nominal public debt. Optimal policy with heterogeneity features a novel inequality-stabilization motive generating higher inflation volatility—but is unaffected by risk, insofar as the target efficient equilibrium entails no inequality.