U.S. worker productivity grew at its quickest pace in three years in the third quarter, depressing labor costs. Nonfarm productivity, which measures hourly output per worker, increased at a 4.7% annualized rate last quarter, the fastest since the third quarter of 2020, the Labor Department said on Thursday. Data for the second quarter was revised slightly higher to show productivity growing at a rate of 3.6% instead of the previously reported 3.5% pace.