Economist Samuel Hammond said Friday that despite a relatively low unemployment rate, there is still a number of unreported cases of unemployment.

"Even the unemployment rate is relatively low, there are still a lot of people on the sidelines who say they're not looking for work," Hammond, director of poverty and welfare policy at the Niskanen Center, told Hill.TV's Jamal Simmons on "What America's Thinking."

"That I think is where a lot of the unease is located. People who have jobs have reason to be optimistic, but there's still a lot of people out there who don't," he continued.

Hammond's comments come after the Labor Department announced the economy added 312,000 jobs in December, while the unemployment rate ticked up to 3.9 percent from 3.7 percent as the labor force expanded by 419,000.

The recent job growth is expected to ease concerns of an impending recession.

The stock market has experienced volatility in recently, raising concerns.

The broader stock index had its worst annual showing since 2008 — when it plunged more than 38 percent during the financial crisis.

— Julia Manchester