*The dramatic spike in oil prices generated 3 months of outsized increases in CPI and PCE inflation that pushed up their yr/yr measures.
*The Fed has kept rates on hold and did not accommodate the negative supply shock, core inflation measures have not increased much, and inflationary expectations have remained anchored.
*Oil prices have fallen sharply, and if current prices stick close to current levels (around or below $75/barrel)—which is uncertain as inventories need rebuilding--continued rapid price declines in gasoline and other energy may result in several months of declines in the CPI and PCE Price Index.
*This would ease some price pressures on consumers and let the Fed breath more easily.
In a note in mid-April, I described how the spike in oil prices from $65/barrel to $95/bbl would temporarily boost the monthly inflation data for about three months as retail prices adjusted to the higher oil prices. I emphasized the importance of the Fed not accommodating the negative supply shock, which would keep its impacts temporary, limit the pass through of the higher oil prices to the prices of nonenergy goods and services, and constrain inflationary expectations. I noted that if oil prices remained around $95/bbl, after several months of outsized increases, the monthly inflation data would revert to their prior increases, while their yr/yr measures would rise to absorb the temporary monthly spikes.
I continued: “However, if oil prices fall, subsequent months' CPI and PCE Price Index data would possibly decline, and the temporary months of deflation would reduce the general price level from its oil price-driven peak.” That process is now beginning to unfold. Yippee: a positive supply shock that involves a partial reversal of the negative supply shock imposed by the conflict in the Middle East and relief to consumers and businesses.
Here’s the situation: in the prior 12 months through February 2026, CPI inflation was 2.4%, averaging a 0.2% increase per month, while PCE inflation was 2.9%, averaging a 0.3% rise per month. The oil price spike pushed up CPI inflation 0.9%, 0.6% and 0.5% in March, April and May, lifting its yr/yr inflation to 4.2% in May, while PCE inflation rose 0.7% and 0.4% in March and April, lifting its inflation to 3.8% in April (PCE inflation for May will be reported tomorrow). See Chart 1. During these months, both core CPI inflation and PCE inflation rose a bit (CPI: 0.2%, 0.4% and 0.2%; PCE: 0.3% and 0.2%), but the details of the CPI indicate that the pass through of the oil price spike was fairly limited to specific categories, including energy services (electricity and utilities) and airline fares. Most categories in the CPI showed little effect of the higher oil prices.

