生活成本的周期性不平等及其对货币政策的影响

Cyclical Inequalityin the Cost of Living andImplications for MonetaryPolicy Ting Lan, Lerong Li, Minghao Li WP/25/264 IMF Working Papersdescribe research inprogress by the author(s) and are published toelicit comments and to encourage debate.The views expressed in IMF Working Papers arethose of the author(s) and do not necessarilyrepresent the views of the IMF, its Executive Board,or IMF management. 2025DEC IMF Working PaperResearch Department Cyclical Inequality in the Cost of Living and Implications for Monetary PolicyPrepared by Ting Lan, Lerong Li and Minghao Li Authorized for distribution by Jaewoo LeeDecember 2025 IMF Working Papersdescribe research in progress by the author(s) and are published to elicitcomments and to encourage debate.The views expressed in IMF Working Papers are those of theauthor(s) and do not necessarily represent the views of the IMF, its Executive Board, or IMF management. ABSTRACT:This paper documents that households with higher marginal propensities to consume (MPCs)tend to consume goods with more flexible prices. Consequently, they face more cyclical and volatile inflationand experience higher inflation following an expansionary monetary policy shock. We embed this MPC-pricestickiness relationship into a tractable multi-sector Two-Agent New Keynesian (TANK) model and analyticallydemonstrate that it dampens the effectiveness of monetary policy, reducing its efficacy by about 15% relative toa benchmark model with homogeneous consumption baskets. Introducing heterogeneous baskets alsogenerates an inherently inefficient flexible-price equilibrium, which gives rise to a novel trade-off betweenstabilization and redistribution. The optimal monetary policy therefore differs qualitatively from the standardTANK policy prescription. RECOMMENDED CITATION:Lan, Ting, Lerong Li, and Minghao Li, 2025, “Cyclical Inequality in the Cost ofLiving and Implications for Monetary Policy,” IMF Working Paper 25/264. Cyclical Inequality in the Cost ofLiving and Implications forMonetary Policy Prepared by Ting Lan, Lerong Li, and Minghao Li1 1Introduction Two questions remain central in monetary economics: the impact of monetary policy on ag-gregate consumption and the optimal design of monetary policy. Recent advances in the Het-erogeneous Agent New Keynesian (HANK) literature contribute to the understanding of thesequestions, emphasizing the critical role of household heterogeneity. A key channel in HANK,known as the redistribution channel (Auclert, 2019; Bilbiie, 2020), shows that the effectiveness ofmonetary policy hinges on the relationship between households’ marginal propensities to con-sume (MPCs) and the cyclicality of theirrealincome, defined as households’ nominal incomeadjusted by the price index they face. However, most theories and applications in the HANK lit-erature assume that households consume the same basket of goods and therefore face the sameprice index. In doing so, these studies largely overlook the differential cyclicality in households’price indexes (or costs of living), concentrating instead on the cyclicality of nominal incomeacross households with different MPCs. In this paper, we argue that it is important to consider the relationship between households’MPCs and the cyclicality of their costs of living, both for understanding the monetary transmis-sion and designing the optimal monetary policy. Our argument unfolds in three steps. First, weempirically document the relationship between households’ MPCs and their costs of living. Wefind that households with higher MPCs face more cyclical and volatile inflation, and experiencehigher inflation following an expansionary monetary policy shock. This is because these house-holds allocate a larger portion of their spending on product categories with more flexible prices.Second, we embed this negative relationship between households’ MPCs and price stickiness ina tractable multi-sector two-agent New Keynesian (TANK) model with heterogeneous consump-tion baskets, demonstrating analytically that this relationship dampens the general equilibriumeffect in monetary transmission. Third, we characterize the optimal monetary policy using theprimal approach and show that accounting for cyclical inequality in household’s costs of livingis crucial for designing optimal monetary policy. Our empirical analysis relies on four datasets: the Panel Study of Income Dynamics (PSID),the US Consumer Expenditure Survey (CEX) microdata, the item-level consumer prices datafrom the Bureau of Labor Statistics (BLS), and the data on frequency of price adjustment con-structed by Nakamura and Steinsson (2008). As is well known, households’ MPCs are typicallynot directly observable. Following Cloyne et al. (2020), we use housing tenure status as a quali-tative proxy for households’ MPCs. Specifically, we estimate household MPCs by leveraging thepanel structure of the PSID and the detailed consumption information from the CEX. Our esti-mation stra