WASHINGTON—U.S. workers’ efficiency improved during the past year at the best pace in nearly a decade, laying groundwork for stronger wage growth and continued economic expansion.

The productivity of nonfarm workers, measured as the output of goods and services for each hour on the job, increased at a 3.6% seasonally adjusted annual rate in the first quarter from the prior three months, the Labor Department said Thursday. From a year earlier, productivity rose 2.4%. That was the best gain year-over-year since the third quarter...