US CENTRAL BANKERS are looking for clues that underlying strength in the economy will underwrite their plans to raise interest rates for a third time this year, a record of their meeting last month showed, as officials wrestled with why inflation remains so low.

USfinancing conditions remain easy, the economy is expected to grow above 2 percent for at least the next two years, and unemployment dropped to 4.2% last month, the lowest since 2001. For all that, inflation rose by a mere 1.4% in the year through August, and forecasters, including those at the Federal Reserve, expect it to remain subdued for a while. They aren鈥檛 sure why. The central bank has missed its 2% inflation target for most of the past five years.

鈥淢any participants expressed concern that the low inflation readings this year might reflect not only transitory factors, but also the influence of developments that could prove more persistent,鈥 according to minutes of the Sept. 19-20 meeting of the rate-setting Federal Open Market Committee. The minutes, released Wednesday in Washington, reeled off a list of potential explanations, ranging from the influence of technology on business pricing and pressure on health-care costs from government policies, to elusive 鈥渃ommon global factors.鈥

US central bankers next meet Oct. 31-Nov. 1 and again on Dec. 12-13. Investors have priced in a roughly 77% chance of another hike by the end of the year, according to trading in fed funds futures contracts, despite anxiety among Fed officials that something may be amiss in models they rely on to predict higher prices as the job market heats up.

鈥淭hese minutes suggest that a majority of policy makers still need to have a hike this year disproven鈥 by weaker economic data, said Michael Hanson, chief USmacro strategist at TD Securities in New York. But 鈥渢hey are willing to concede that the risk on inflation鈥 remaining too low is higher than before.

Several policy makers said their decision on whether to raise rates this year 鈥渨ould depend importantly on whether the economic data in coming months increased their confidence鈥 on inflation rising toward target. The policy decision doesn鈥檛 hinge on inflation reports alone, but whether the mix of data continues to point to an economy that is pushing the edges of its capacity.

Data out since the meeting showed indicators of US service sector and manufacturing activity rose in September to the highest in more than a decade, though that partly reflected slow supplier deliveries related to disruption after hurricanes battered Texas and Florida.

鈥淭hey have less confidence in how inflation is behaving, but are much more comfortable that moderate growth is apt to persist,鈥 said R.J. Gallo, a fixed-income investment manager at Federated Investors in Pittsburgh.

At the meeting, the US central bank left the target range for the federal funds rate unchanged at 1% to 1.25%, while projecting another increase before the end of the year and announcing an October start for a gradual unwind of its $4.5-trillion balance sheet.

Getting a clear read on economic data may be difficult as some prices, such as gasoline, are affected by the hurricanes. The Fed鈥檚 post-meeting statement on Sept. 20 said the storms would affect the economy in the near term but were 鈥渦nlikely to materially alter鈥 its course over the medium term.

The minutes said Fed policy makers expected third-quarter growth 鈥渢o be held down by the severe disruptions caused by the storms but to rebound beginning in the fourth quarter as rebuilding got under way and economic activity in the affected areas resumed.鈥

Even though the administration of President Donald Trump and Republicans in Congress say tax reform is a top priority, most Fed officials had either not assumed any fiscal stimulus in their projections made in September, the minutes said, 鈥渙r had marked down the expected magnitude of any stimulus.鈥

Many officials said USfinancial conditions would support the economic expansion, while a couple of policy makers 鈥渆xpressed concern that the persistence of highly accommodative financial conditions could, over time, pose risks to financial stability,鈥 the minutes said.

The minutes said 鈥渕any鈥 participants 鈥渃ontinued to believe鈥 that labor-market pressures would eventually show through to higher inflation. 鈥 Bloomberg