In a powerful rebound from 2020, when the economy contracted by 3.4 percent — its worst result since 1946 — 2021′s strong growth created a record 6.4 million jobs. But it also brought a host of complications, helping fuel the highest inflation in 40 years and creating supply chain snarls as consumers hungry for products overwhelmed the global delivery system. To beat back rising prices, the Federal Reserve is now shifting its strategy and preparing for interest rate hikes this year, convinced it has given enough support to help the labor market and now must keep the economy from overheating further.