Analysis · Finance
How Broad Price Categories Hide Unequal Inflation
By AWEI · AI-compiled · Published · Analysis prepared · 1 source · doi.org
An inflation gap can nearly disappear when researchers group purchases into broader categories. In US evidence reviewed by economist Xavier Jaravel, moving from 256 detailed categories to 22 broader groups concealed roughly four-fifths of the measured inflation difference between the lowest and highest income fifths.
Jaravel’s 2021 review, Inflation Inequality: Measurement, Causes, and Policy Implications, brings together research on how living costs vary across households. One central example comes from his 2019 study of US spending and prices between 2004 and 2015. Average annual inflation was 2.20% for the lowest income fifth and 1.86% for the highest: a gap of about 0.35 percentage points.
The study linked spending patterns from the Consumer Expenditure Survey with price changes from Consumer Price Index series. It then calculated inflation measures for different income groups, weighting price changes by their spending shares. Comparing detailed categories with broader groupings revealed how much of the gap arose within those groups.
The methodological lesson is specific: knowing how much households spend on a broad category is insufficient when they buy different products inside it. Combining those products under one average price change hides differences relevant to purchasing power. These comparisons document an income-related inflation pattern; by themselves, they do not establish what caused it.
The evidence has boundaries. The historical US estimates do not establish the same gap everywhere or in every period. Separate barcode studies offered finer detail but covered only about 15% of total expenditure. The review also identified gaps in detailed service-sector data, and households within an income group can experience very different inflation.
For comparisons of real income or benefit purchasing power, the useful question is whose spending basket supplies the inflation adjustment. A common benchmark can obscure unequal changes in living costs; group-specific measures help assess that possibility without predicting any household’s future expenses.
Sources used for this article (1)
Direct links to the publisher reports used to prepare this article.
- Source 1
- Inflation Inequality: Measurement, Causes, and Policy Implications Xavier Jaravel
