Former U.S. Treasury Secretary Lawrence Summers said investors need to brace for the Federal Reserve to potentially raise interest rates at all seven remaining policy meetings this year and even for it to hike by more than a quarter point in one go.

“Markets have to be prepared for a rate hike in every meeting and they have to be prepared for the possibility that, as the inflation process continues, we might need to have meetings with more than a single 25 basis point rate hike,” Summers told Bloomberg Television Friday.

The Fed is “behind the curve” and anyone not open to considering that policy makers will boost rates at consecutive meetings through year-end is “underestimating the range of possibilities,” said Summers, a Harvard University professor and paid contributor to Bloomberg.

Summers in December had suggested that signaling four hikes in 2022 was what would be “required to restore credibility” to the Fed with regard to quelling inflation. But since then, price and wage gains have accelerated further. Fed Chair Jerome Powell last week indicated the central bank will lift rates from near zero in March, and left the door open to doing more later.

Bank of America Corp. stands out among major Wall Street banks in forecasting rate increases at all the remaining policy meetings this year, while Nomura Holdings Inc. drew attention last week in predicting the Fed will deliver the first half-point increase since 2000.

“The data are very uncertain, and we’ve all got to recognize and be humble about that,” said Summers on Friday.

Summers praised Powell for saying he would be “humble” and “nimble” with regard to setting policy, but also cautioned that the Fed will likely need to tighten by more than it now assumes.

“The greater risk is that we under-tighten and that we end up with an economy with underlying inflation above 4% — and then there is no alternative at some point to do the kind of thing that Paul Volcker had to do at the end of the 1970s,” said Summers. “An error of allowing inflation to become entrenched would be a very real and grave error.”

Further evidence of inflation pressures came Friday, with the monthly employment report for January showing average hourly earnings rising 0.7% from December — the most since the end of 2020.

“It sure looks like we’ve now got wage inflation in the United States at a rate that is very strong,” said Summers. “We’re moving towards entrenching inflation at well above the target 2% rate.”