CPI and PCE: Two Measures of Inflation and Fed Policy
The BEA's core Personal Consumption Expenditures (PCE) Price Index for August shows that core inflation continues to be above the Federal Reserve's 2% long-term target at 3.9%. The August core Consumer Price Index (CPI) release was higher, at 4.3%. The Fed is on record as using core PCE data as its primary inflation gauge. For a closer look at each of those releases, check out our latest Consumer Price Index and PCE Price Index releases.
Preferred Inflation Gauge
The Fed is on record as using core PCE data as its primary inflation gauge.
The inflation rate over the longer run is primarily determined by monetary policy, and hence the Committee has the ability to specify a longer-run goal for inflation. The Committee judges that inflation at the rate of 2 percent, as measured by the annual change in the price index for personal consumption expenditures, is most consistent over the longer run with the Federal Reserve's statutory mandate. Communicating this inflation goal clearly to the public helps keep longer-term inflation expectations firmly anchored, thereby fostering price stability and moderate long-term interest rates and enhancing the Committee's ability to promote maximum employment in the face of significant economic disturbances. [Source] Note: bolding added.
Elsewhere, the Fed stressed the importance of longer-term inflation patterns, the likelihood of persistence and the importance of "core" inflation (less food and energy). Why the emphasis on core inflation? Here is an excerpt from one of the Fed FAQs.
Finally, policymakers examine a variety of "core" inflation measures to help identify inflation trends. The most common type of core inflation measures excludes items that tend to go up and down in price dramatically or often, like food and energy items. For those items, a large price change in one period does not necessarily tend to be followed by another large change in the same direction in the following period. Although food and energy make up an important part of the budget for most households — and policymakers ultimately seek to stabilize overall consumer prices — core inflation measures that leave out items with volatile prices can be useful in assessing inflation trends. [Source]
PCE and CPI: A side-by-side comparison
This close-up comparison gives us clues as to why the Federal Reserve prefers core PCE over core CPI as an indicator of its success in managing inflation: Core PCE is considerably less volatile than CPI. Given the Fed's twin mandates of price stability and maximizing employment, it's not surprising that, in the past, the less volatile core PCE has been its metric of choice. On the other hand, the disinflationary trend in core PCE (prior to 2022) casts doubt on the effectiveness of the Fed's monetary policy.