Nonfarm employers added 312,000 new hires in December, and the number of jobless workers increased 276,000 to 6.3 million, the Bureau of Labor Statistics reported.

The December rate of unemployment rising to 3.9 percent from 3.7 percent in November "happened for the ‘right’ reasons as more workers entered the labor force — the labor force participation rate ticked up 0.2 percentage points," according to Elise Gould, an economist with the Economic Policy Institute in Washington, D.C.

Gould credits government spending and the tax bill for improving job growth. "A year earlier, the jobless rate was 4.1 percent, and the number of unemployed persons was 6.6 million," the BLS reported.

In December for two major groups of workers, adult men and African-Americans, unemployment rates rose. For adult women, teens, whites, Asians, and Hispanics the jobless rate "showed little or no change over the month."

Workers’ wages grew in 2018. "Over the year, average hourly earnings have increased by 84 cents, or 3.2 percent," according to the BLS. A fall in the unemployment rate tends to push employers to hike pay for a shrinking pool of job seekers.

On January 1, 2019, 19 states raised their minimum wages. That action will hike hourly earnings for 5.3 million workers nationwide.

In December and for the third consecutive month, the employment-population ratio was 60.6 percent (the share of the labor force now on payrolls versus the total working-age population).

Midsize employers (50-499 employees) led the way with 129,000 new hires in December versus 119,000 new hires in November,according to the ADP National Employment Report. Small businesses (1-49 employees) added 89,000 new jobs in December compared with 46,000 in November. Companies of 500 or more workers hired 54,000 employees in December versus 13,000 employees in November. National franchise employment rose 29,000 in December compared with 11,500 in November.

ADP’s National Employment Report totals America’s nonfarm private sector employment from existing payroll data, according to the ADP Research Institute that works with Moody’s Analytics. ADP reports payroll data for 411,000 American private-sector clients employing nearly 24 million workers nationally. (The BLS surveys businesses and households and counts government jobs.)

According to ADP’s report, the service sector of the economy grew by 224,000 jobs in December versus 163,000 new hires in November. Professional and business services employment rose 66,000 in December, up from 59,000 in November. In December, there were 33,000 new hires in trade, transportation and utilities compared with 18,000 in November. Education and health added 61,000 jobs in December versus 49,000 in November.

Payrolls in the goods-producing sector expanded by 47,000 jobs in December versus 16,000 jobs in November. Construction firms added 37,000 new hires in December versus 10,000 new hires in November. Manufacturing companies hired 12,000 new workers in December compared with 4,000 in November.

"We wrapped up 2018 with another month of significant growth in the labor market," said Ahu Yildirmaz, vice president and co-head of the ADP Research Institute, in a statement. "Although there were increases in most sectors, the busy holiday season greatly impacted both trade and leisure and hospitality. Small businesses also experienced their strongest month of job growth all year."

Mark Zandi is the chief economist of Moody’s Analytics. "Businesses continue to add aggressively to their payrolls despite the stock market slump and the trade war," he said. "Favorable December weather also helped lift the job market. At the current pace of job growth, low unemployment will get even lower."

Economic headwinds to watch range from the China-U.S. trade conflict, stock turmoil to the Federal Reserve Bank raising interest rates in 2019.