Core Inflation

Core inflation strips out the most volatile categories—typically food and energy—from a headline price index such as the Consumer Price Index (CPI) or the Personal Consumption Expenditures (PCE) index. The goal is to isolate the persistent, demand-driven component of inflation from short-term shocks like oil price spikes or harvest failures, which tend to reverse and can mislead policymakers if treated as trend.

The concept is generally traced to economist Robert J. Gordon, who in the 1970s argued that excluding volatile items produced a more reliable signal of underlying price pressures during the oil shocks of that decade. Central banks have since adopted core measures as a key input—though not the sole target—for monetary policy decisions.

Common variants include:

• Core CPI (United States): CPI excluding food and energy, published monthly by the Bureau of Labor Statistics.
• Core PCE: The U.S. Federal Reserve's preferred gauge for assessing progress toward its 2% inflation objective.
• HICP excluding energy and unprocessed food: Used by the European Central Bank alongside other underlying measures.
• Trimmed-mean and median CPI: Alternative "underlying" measures produced by the Federal Reserve Banks of Cleveland and Dallas that drop the most extreme price changes each month rather than fixed categories.

Critics note that food and energy are unavoidable expenses for households, so core inflation can understate the cost-of-living pressure felt by lower-income consumers. Defenders respond that headline and core inflation tend to converge over time, and that reacting to every energy shock would force central banks into procyclical policy errors.

During the 2021–2023 global inflation surge, divergence between headline and core readings became politically salient: headline inflation in many OECD economies peaked above 8–10% on energy costs, while core measures remained more moderate but proved stickier, prolonging tightening cycles by the Fed, ECB, and Bank of England.