FRANKFURT—The European Central Bank’s two leading economic thinkers sparred on Thursday over how likely it was for the recent, sharp rise in euro zone inflation to become permanent. Philip Lane and Isabel Schnabel, who lead the economic debate on the ECB’s board, both repeated the ECB’s official line that the spike in price growth would ease next year as the effects of a post-pandemic bounce fade. But they differed sharply on the risks surrounding that prediction, with Schnabel warning of “more persistent inflationary pressures” and Lane of forces that could drag down price growth. “It would be premature to assert that current price dynamics will fully subside next year,” Schnabel told a joint conference organised by the ECB and the Cleveland Federal Reserve. “There are several sources of uncertainty that might entail more persistent inflationary pressures.” Among them, she listed potential changes in inflation expectations and in people’s behaviour when …