CPI vs PCE: What's the Difference and Why the Fed Prefers PCE

When the news says "inflation came in at 3%," it matters which index they mean. The United States publishes two headline inflation measures — the Consumer Price Index (CPI) and the Personal Consumption Expenditures (PCE) price index — and in any given month they rarely agree. PCE usually runs a bit lower. Here is why.

Two Inflation Gauges, Two Agencies

The CPI is produced by the Bureau of Labor Statistics (BLS) from direct retail price surveys; it measures what urban households pay out of pocket. The PCE price index is produced by the Bureau of Economic Analysis (BEA) as part of the national accounts (GDP statistics); it measures the price of all consumption by the household sector — no matter who pays the bill.

The Four Big Differences

• Scope: PCE includes spending made on your behalf — most importantly, health care paid by employers and government programs. CPI counts only what consumers pay themselves, which is why medical care carries a much larger weight in PCE.
• Weights: Shelter dominates the CPI (housing-related items exceed 30% of the index), while its weight in PCE is much smaller. In a year of soaring rents, CPI inflation gets pushed up more than PCE.
• Formula: CPI uses a near-fixed-weight formula; PCE uses a chained formula that captures substitution — consumers switching from beef to chicken when beef gets expensive. This formula effect is a major reason PCE inflation typically runs about 0.2–0.4 percentage points below CPI.
• Population: CPI-U covers urban consumers only; PCE covers all households plus nonprofit institutions serving them.

Why the Fed's 2% Target Is Tied to PCE

The Federal Reserve switched its primary inflation gauge to the PCE price index in 2000, and the FOMC's January 2012 Statement on Longer-Run Goals made it official: the 2% inflation objective is defined in terms of the annual change in the PCE price index. The Fed's stated reasons: PCE covers a broader range of spending, its weights adjust to changing behavior, and its history can be revised as better data arrive. So while headlines quote CPI, the number on the table at FOMC meetings is PCE.

Which One Should You Watch?

Neither is "wrong" — they answer different questions. CPI tracks the out-of-pocket cost of living and is the standard reference for leases, wage negotiations, TIPS, and Social Security adjustments. PCE is the key series for reading monetary policy. For long-run purchasing power comparisons, CPI has the decisive advantage of history: a continuous series since 1913.