Jerome Powell still believes US inflation will wind down as supply chains get untangled next year—but now he also sees a growingrisk of high prices lingering for much longer.

On Dec. 15, the US Federal Reserve said it is speeding up the phaseout of its bond buying program, and signaled it could hike interest rates as early as next spring. “There’s a real risk now,” Powell said at a press conference to explain the decision. “I believe that inflation may be more persistent…the risk of higher inflation becoming entrenched has increased.”