Trimmed Mean PCE

What Is Trimmed Mean PCE?

The Trimmed Mean PCE inflation rate is a Dallas Fed Reserve product that produces a more robust read on the central tendency of inflation than core or headline measures. It is constructed by ordering all PCE components by their monthly price change and removing the most extreme outliers in either direction before averaging.

The specific methodology trims the bottom 24% and top 31% of the expenditure-weighted distribution each month. The asymmetric trim reflects the empirical observation that monthly price changes are right-skewed (more frequent and larger upside outliers than downside). The Dallas Fed has published the series since 2009; the FRED ticker is PCETRIM12M656N for the 12-month rate.

Why It Matters for Markets

Trimmed mean PCE filters out the noise that distorts other inflation measures. When used cars or airfares spike for category-specific reasons, core PCE captures the spike fully but trimmed mean automatically removes it. The result is a measure that more reliably reflects underlying inflation rather than the noise of any single category.

Fed officials reference trimmed mean in speeches and minutes, especially when defending policy turns. When trimmed mean and core PCE diverge, the trimmed mean usually wins the interpretation. Markets that learn to watch trimmed mean alongside core have a cleaner read on Fed reaction-function signals.

How to Read the Print

Three things to track:

Trimmed mean vs core PCE. A persistent gap (trimmed mean below core, or vice versa) signals that core's two excluded categories are distorting the picture in one direction. The gap widened in 2021 (core understated trimmed mean as used cars spiked and were not in food/energy) and reversed in 2023 (core overstated trimmed mean as housing services ran hot but were trimmed out).

Trimmed mean 1-month and 6-month annualised rates. The 12-month is the headline number but the high-frequency reads catch turning points first.

Breadth of price changes. The Dallas Fed publishes the distribution of monthly price changes alongside the trimmed mean. A wider distribution means more categories are at extreme values; a narrower distribution means the trim is doing less work and underlying inflation is closer to the trimmed-mean read.

Historical Context

Trimmed Mean PCE peaked at 4.7% YoY in October 2022, lower than core PCE's 5.6% peak in the same cycle, because the trim was removing extreme outliers in both directions. By 2024 it had decelerated to roughly 2.7-2.9%, broadly tracking core PCE's path.

The 2010-2019 average was approximately 1.8%, slightly above core PCE for the same period. The convergence in the late stages of the cycle has been one of the cleanest signals that the inflation surge of 2021-2023 has been broadly digested rather than displaced into other categories.