The national economy added about 155,000 new jobs in December, but that was not enough to improve the U.S. unemployment rate of 7.8 percent.

At this pace, the economy will need until 2020 to replace the jobs lost since the recession. But local economists said they expect the pace of recovery to improve in 2013.

“You hope for a good tourism season,” said Richard Perniciaro, director of the Center for Regional and Business Research at Atlantic Cape Community College.

“Nobody wants to chase ambulances, but the damage caused by Hurricane Sandy (in central New Jersey) might turn out to be to our benefit in Atlantic and Cape May counties.”

About 12.2 million Americans were unemployed nationally in December, slightly more than in November, according to numbers released Friday by the U.S. Bureau of Labor Statistics. More than one-third of those workers, 4.8 million, are considered long-term unemployed, having been without a job for 27 weeks or more.

The national unemployment rate remained at 7.8 percent, little changed since September and the same as November’s revised rate (up from 7.7 percent). This compares with New Jersey’s unemployment of 9.6 percent in November. The state’s unemployment rate was 9.9 percent in August — the highest rate the state has seen in 35 years.

Of the Americans who are employed, almost 8 percent are working only part time because of a lack of full-time hours. And the labor force does not reflect another 1.1 million “discouraged” workers who are no longer seeking employment because of the scarcity of jobs. This is part of a larger 2.6 million Americans who were not counted among the unemployed because they had not sought work in the four weeks before the federal survey. These workers are available for work and have sought a job within the past year.

“Once people start seeing the unemployment rate go down and jobs becoming available, those discouraged workers will come back into the work force,” Perniciaro said. “It’s a matter of the pace of job growth. Once you get into a situation where people believe in the recovery, the pace of recovery will speed up.”

In southern New Jersey, Atlantic and Cape May counties had unemployment rates of 14.5 percent in November based on the most recent numbers (not seasonally adjusted) from the state Department of Labor. About 20,200 people were unemployed in Atlantic County; 8,400 workers were jobless in Cape May County. Cumberland County had a jobless rate of 12.9 percent. Ocean County’s unemployment was 11.2 percent in November.

Nationwide, the industries that saw improvement in December included health care, manufacturing and the construction trades, which added 30,000 new jobs.

Builder Brad Haber, of the Egg Harbor City firm Brad Haber Homes, said a slow housing market continues to dog New Jersey’s construction industry.

“We get a lot of ‘oohs’ and ‘aahs,’ but we’re not getting ink on the paper,” he said. “People are still very uncertain. Almost everyone has a different reason for being uncertain.”

Haber said he expects New Jersey to follow the national trend in 2013 in seeing gradual improvement in home sales. Eventually, this will create a critical mass of new jobs that, in turn, will sustain the housing market.

“Once housing gets people back to work, it will have a positive effect,” he said.

About 38,000 of the jobs created in December were in bars, restaurants and other food services.

A study in August by the nonprofit National Employment Law Project found that the recession shed the most jobs among mid-wage occupations. But since 2010, the most job growth has been observed among lower-wage occupations, said Anastasia Christman, a senior policy analyst for the nonprofit, nonpartisan group based in New York.

Lower-wage occupations accounted for 21 percent of the jobs lost during the recession and 58 percent of the job growth since the recession. Mid-wage jobs accounted for 60 percent of the recession losses but so far has accounted for just 22 percent of the recovery.

High-wage jobs made up 19 percent of recession losses and about 20 percent of the recovery growth.

“A significant difference between this recovery and other recoveries has been a lack of bounce-back in the public sector,” Christman said. “Local governments have had to make a lot of layoffs. Those are quality mid-wage jobs.”

Contact Michael Miller: