What We Know About September's US CPI Inflation Report

The U.S. Bureau of Labor Statistics is expected to report that headline inflation for September picked up from the previous month, driven primarily by a rise in gasoline prices, according to a preview published by Bloomberg. The same preview notes that underlying, or core, price pressures continued to moderate even as the top-line figure climbed, a split that reinforces market expectations the Federal Reserve will leave interest rates unchanged when it meets later this month, Bloomberg reported.

What is the September CPI report expected to show?

Bloomberg's preview frames September's Consumer Price Index as a report of two tracks: a faster overall reading pulled up by gasoline, and a slower core reading that strips out food and energy. The agency's framing suggests the headline number will overstate the pace of broad-based price pressure in the economy, since a single volatile category — fuel — is doing most of the lifting. The report, once released, typically covers price changes across categories including energy, food, shelter and transportation, though only the gasoline-driven headline move and the core moderation are detailed in the material reviewed here. Bloomberg did not break out specific percentage changes in that preview.

Why would higher gasoline prices move the headline number?

Gasoline is one of the most heavily weighted and most volatile components inside the CPI basket, and even modest swings at the pump can move the overall index more than changes in categories such as housing or apparel. Bloomberg's preview identifies gasoline as the lead driver of the expected September increase without detailing the cause of the price rise itself.

"Higher gasoline prices probably led to quicker overall U.S. inflation in September even as underlying price pressures moderated," Bloomberg reported.

How does a cooling core rate change the Fed's calculus?

The Federal Reserve generally weighs core inflation more heavily than the headline figure when setting policy, on the theory that energy prices swing for reasons unrelated to the broader economy's health. Bloomberg's preview says the expected moderation in core prices supports views that the central bank will refrain from raising rates at its meeting this month — language that points toward a hold rather than a hike, based on the reporting reviewed.

What should readers watch for when the full report is released?

• Whether the headline CPI figure comes in above, at, or below the pace analysts expect, given the gasoline effect flagged by Bloomberg.
• Whether core CPI — the figure that excludes food and energy — continues the moderating trend described in the preview.
• Any statement from Federal Reserve officials tying the report directly to the October rate decision.
• Follow-on moves in gasoline futures or retail pump prices that could signal whether the fuel-driven bump is temporary.

Where can readers find the original data?

The CPI figures themselves are published by the Bureau of Labor Statistics, and Bloomberg's analysis of the September release is available in the originating report. No additional percentage breakdowns, release-date specifics or official BLS figures were included in the material reviewed for this article, and none are added here.