U.S. Jobless Rate Falls as Wages Jump, Adding Pressure on Fed

The U.S. unemployment rate fell below 4% and wages jumped last month, adding to evidence of a tight labor market that’s expected to help spur Federal Reserve interest-rate liftoff as soon as March despite disappointing payroll growth.

The jobless rate dropped to 3.9% and monthly wage growth accelerated in December, a Labor Department report showed Friday. A 199,000 increase in nonfarm payrolls followed upward revisions in the prior two months, and the labor force participation rate was unchanged.

The latest employment numbers suggest that despite still-robust labor demand, the factors...