欧洲央行-通货膨胀风险和异质性下降（英）

Working Paper Series Inflation risk and heterogeneous trading down Mar Domenech Palacios Disclaimer: This paper should not be reported as representing the views of the European Central Bank (ECB). The views expressed are those of the authors and do not necessarily reflect those of the ECB. No 3156 AbstractI examine how households adjust the quality of their purchases in response to ad-verse economic shocks.Using household scanner data from Germany, I documentheterogeneous responses across income levels. Higher-income households tend to re-duce the quality of the goods they purchase, whereas lower-income households, whotypically consume lower-quality goods, show a limited propensity to trade down, likelydue to a limited ability to do so. To assess the equilibrium effects of an aggregate shiftin demand toward lower-quality varieties, I implement a shift-share research design.This approach leverages two key components: (i) pre-determined spending shares onmiddle-quality varieties across the product space for a wide range of sociodemographicgroups prior to the great financial crisis, and (ii) variation in population growth acrossthese groups during the crisis. I find that a 1% aggregate demand shift toward lower-quality varieties following a recession raises the relative price of low-quality varietiesby about 0.45% on average.JEL Classification: E21, E31, E32, E60Keywords: inflation, prices, business cycle, quality, trading downECB Working Paper Series No 315611Non-technical summaryInflation does not affect all households in the same way. Differences in income, spending patterns,and product choices mean that the cost of living can rise faster for some families than for others.While earlier research has shown that low-income households often experience higher inflationthan wealthier ones, less is known about how these differences evolve during recessions andperiods of economic stress.This study explores a new mechanism that helps explain such inequality, which I refer to asheterogeneous trading down. When the economy deteriorates, households may respond by sub-stituting toward cheaper or lower-quality versions of the same goods. Using detailed supermarketscanner data covering purchases by German households between 2005 and 2018, I investigatehow this behaviour varies across income levels and how it shapes the inflation experienced bydifferent groups.The findings show clear differences across the income distribution. Higher-income householdstend to reduce the quality of their purchases during downturns, effectively protecting their realconsumption by trading down to cheaper varieties. In contrast, many lower-income householdsalready consume the lowest-quality goods and therefore have little scope to adjust further.Approximately 10–20% of households are at this “quality lower bound” and cannot trade down.As a result, low-income households are less able to cushion themselves against economic shocks.This asymmetry has important aggregate effects. When a