You can't say America isn't creating jobs.

The unemployment rate is down to 5.1%, and the nation has more than recovered all the jobs it lost during the Great Recession.

But Bernie Sanders is arguing that those jobs aren't very good.

On Twitter this week, the Democratic presidential candidate said: "Most of the jobs that are being created today pay less than most of the jobs that were lost during the financial crisis."

Strong statement, but is it true?

To back up the claim, Sanders' campaign points to two studies from last year. One, from the National Employment Law Project, a left-leaning advocacy group, found that there were 1.85 million more people employed in lower-wage industries at the start of 2014 than at the beginning of the recession. But there were nearly 2 million fewer jobs in mid-wage and higher-pay industries.

The second, from the U.S. Conference of Mayors, found that jobs gained during the recovery paid an average 23% less than those lost during the recession, or only $47,170, compared to $61,637.

That's because the top sectors that downsized were manufacturing and construction, which offered relatively high wages. The sectors that added jobs were accommodation and food services, as well as health care, both of which paid less, on average.

It's true, but Sanders' claim is a bit outdated. Employers now filling higher-paying positions.

In August alone, professional service jobs, such as lawyers and accountants, grew by 33,000, while financial services gained 19,000 jobs.

"In the past year, job gains in high-wage sectors have accelerated and we expect that to continue," said Jim Diffley, senior director at IHS Economics, which conducted the U.S. Conference of Mayors report.

Some 44% of the jobs created through the end of 2014 were good jobs, paying more than $53,000 a year, according to a report released last month by Georgetown University's Center on Education and the Workforce.

Georgetown's study also looked at occupations, versus the mayor's conference and law project, which tracked which industries were adding positions.

"If what [Sanders] means is we are creating lousy jobs, that's not true," said Anthony Carnevale, who directs the Georgetown center.

This is not to say that workers are seeing big wage hikes. The median hourly wage has declined 4% between 2009 and 2014, with lower-paid workers suffering from the largest drops, according to a new report from the law project.

"The signs of improvement have eluded most workers in terms of their paychecks," said Claire McKenna, policy analyst at the law project.