Federal Reserve Governor Jerome Powell said the central bank’s asset purchases may be scaled back later this year if growth holds up, and any such trimming depends on economic data rather than the calendar.

The Fed may wait “before moderating purchases or even increase them” if the economy weakens, while the large-scale asset purchases “may be moderated somewhat more quickly” should the economy strengthen faster than officials anticipate, Powell said in the text of remarks prepared for delivery in Washington.

“I want to emphasize the importance of data over date,” Powell said at the Bipartisan Policy Center, where he was a visiting scholar before joining the Fed. “In all likelihood, the current” large-scale asset purchases “will continue for some time.”

Policy makers are debating when to wind down $85 billion in monthly bond purchases that have pushed the Fed’s balance sheet to a record $3.47 trillion in the most aggressive easing in the central bank’s 100-year history. Chairman Ben S. Bernanke said last week the Federal Open Market Committee could start reducing purchases later this year and end them around the middle of next year if the economy meets the Fed’s forecasts.

“The LSAPs continue to provide meaningful support for economic activity,” Powell said. “Although the channels may not be working perfectly, it is unlikely that they are not working at all.”

Largest Economy

Powell said the world’s largest economy probably “will continue to gain strength” and that the labor market “has also made real progress” despite federal budget cuts that may be “preventing faster reductions in unemployment.” While inflation gauges have declined below the Fed’s 2 percent target, he said there is “some reason to think that the recent low readings partly reflect transitory factors.”

Even after the Fed started holding its main interest rate near zero in December 2008, that month was the last time the world’s largest economy had a jobless rate of less than 7.5 percent. Fifteen of 19 FOMC participants expect the first rate increase to be in 2015 or later, forecasts released after their June 18-19 meeting showed. They project unemployment, which was 7.6 percent in May, will fall to 6.5 percent to 6.8 percent by the end of 2014.

Borrowing Costs

The Fed in December linked changes in the benchmark borrowing cost to the outlook for employment and prices. The FOMC said the rate will remain in a range of zero to 0.25 percent so long as unemployment remains above 6.5 percent and the outlook for inflation is no higher than 2.5 percent.

The U.S. economy has continued its four-year expansion even amid across-the-board government spending cuts as consumers boosted spending and propelled gross domestic product to a lower-than-projected 1.8 percent annual pace in the first quarter.

A slowdown in inflation has given Fed officials more leeway for easing. The personal consumption expenditures price index rose 0.7 percent for the year through April, the lowest since October 2009 and below the FOMC’s 2 percent target.

Excluding food and fuel, consumer prices climbed 1.1 percent in the 12 months through April, matching the smallest increase since records began in 1960, according to a so-called core measure watched by the Fed.

Powell, 60, an attorney and private equity investor who was a Treasury undersecretary for President George H.W. Bush., took office as a governor in May 2012. He was a partner at the Carlyle Group LP, a private-equity firm, from 1997 through 2005.