The Federal Reserve got a tougher inflation signal than markets had hoped for in September. Core CPI, which strips out food and energy, did not slow. The monthly increase stayed at 0.3% for a second straight month, above the 0.2% consensus expectation, while shelter inflation stopped easing and non-housing services also firmed.
In Gianluca Benigno’s latest analysis, higher oil prices alone do not automatically require another rate increase. But if energy remains elevated and core inflation still refuses to cool, the argument for waiting becomes harder to sustain. On that reading, the September CPI report strengthened the case for further tightening and left the October meeting as a live option.
Core CPI beat expectations again
The part of the September CPI report most likely to concern the Fed was the lack of progress in underlying inflation.
Core CPI rose 2.6% from a year earlier, above the 2.5% market forecast and August’s 2.4%. On a seasonally adjusted monthly basis, it increased 0.3%, unchanged from August and marking the second month in a row above the expected 0.2%.
Headline CPI rose 3.7% year over year and 0.6% on a seasonally adjusted monthly basis. Gasoline prices climbed 9.1% from the previous month and accounted for more than half of the monthly increase in headline CPI, showing that energy was still the main driver of the broader price gain.
What made the report more consequential for policy was that stronger energy prices and sticky core inflation appeared at the same time. Even after setting aside oil-price swings, the pace of price increases across other consumer categories did not cool in the way markets had expected.
Benigno said the move in annual core CPI from 2.4% to 2.6% should be read carefully. By his calculation, the unrounded year-over-year figure actually rose from about 2.45% to 2.56%, an increase of roughly 0.11 percentage point. A low base from the same period last year also amplified the published annual reading.
That means the reported 0.2 percentage point increase should not be taken as proof that core inflation suddenly reaccelerated sharply. The more important signal for policy came from the monthly trend: the expected slowdown did not arrive, and 0.3% monthly core CPI printed again. Benigno said that was not enough on its own to confirm a new inflation upswing, but it did leave the Fed without clear evidence that would justify a comfortable pause.
Shelter and services both firmed
The internal composition of core inflation carried more weight than the headline core figure alone.
Shelter had previously been seen as a major channel through which core inflation could continue to slow. In September, that process stalled. Shelter prices rose 3.2% from a year earlier, up from 3.0% in August, while the seasonally adjusted monthly gain accelerated to 0.4% from 0.3%. Shelter contributed about half of the monthly rise in core CPI.
Within shelter, owners’ equivalent rent — an estimate of the rental value of owner-occupied housing services — increased 0.3% on the month, up from 0.2%. Rent of primary residence held at 0.2%.
Part of the annual pickup in shelter reflected a low base, but the faster seasonally adjusted monthly increase also pointed to a real change in recent price behavior. For the Fed, that matters because one of the components expected to keep pulling core inflation lower did not deliver in September.
Outside shelter, services inflation also stayed resilient. Core services excluding shelter, often referred to as “supercore” services, rose 3.2% from a year earlier, up from 3.1%, while the seasonally adjusted monthly increase held at 0.3%.
Transportation services rose 0.6% on the month, including a 1.2% increase in airfares. Hospital services and education services rose 0.7% and 0.6%, respectively. Benigno said stronger transportation services prices suggest higher energy costs may be starting to feed into some service categories. At the same time, medical care, education, and shelter each have different price drivers, so those increases cannot all be attributed to oil.
That leaves the Fed with a harder policy mix. Energy pressure has not faded, and shelter and other services are not providing enough disinflationary force. If that combination persists, waiting becomes a less convincing strategy for policymakers looking for evidence that inflation will fall back on its own.
Goods inflation remained less alarming
Goods data still offered a more moderate signal.
Core goods prices rose 0.7% year over year in September, unchanged from August. Apparel inflation slowed to 3.4% from 3.6%. The seasonally adjusted monthly increase in core goods accelerated to 0.3% from 0.1%, but there was still no broad sign of year-over-year acceleration across the category.
In Benigno’s framing, the better description of the current backdrop is that core inflation has become stickier, not that all parts of the economy have entered a generalized price upswing.
October hike case strengthened, but not settled
The Fed had already raised rates by 25 basis points at its September meeting, taking the target range for the federal funds rate to 3.75%-4.00%. All 12 voting members supported that decision. The policy statement said economic activity had been expanding at a solid pace, domestic spending remained resilient, and inflation was still elevated.
Against that backdrop, the September CPI report effectively tested whether underlying inflation was still easing enough to give the Fed grounds to pause and assess the effects of earlier tightening. The report did not provide the support markets had been looking for.
With monthly core CPI failing to cool and both shelter and non-housing services showing strength, the case for simply waiting after the September hike became weaker. Still, one report cannot capture the full effect of the previous increase, and monetary policy takes time to feed through to demand and prices.
Benigno’s interpretation leans toward more tightening. Based on his view of the Fed’s reaction function, policymakers will weigh how long inflation remains above target, how resilient growth and employment still are, and whether financial conditions are restrictive enough to curb demand.
If the economy stays firm, the labor market does not materially weaken, and core services inflation remains strong, the case for another hike would become stronger. If later data show a clear cooling trend, or if financial conditions tighten meaningfully, a pause would still have support.
He also drew a distinction between inflation gauges. The Fed targets 2% inflation through the PCE price index. Core CPI is an important reference point, but the gap between core CPI and 2% cannot be mechanically translated into a number of future rate hikes.
For the October 27-28 meeting, the next data points to watch include producer prices, inflation expectations, employment, and financial conditions. Whether shelter and non-housing services resume cooling will shape how the Fed judges the persistence of price pressure.
The September CPI report did not make an October hike a foregone conclusion. It did, however, raise the evidentiary bar for a pause. If the Fed decides to wait again while core inflation has not cooled as expected, it will need stronger support from the rest of the incoming data.