At the worst point around the Great Recession, one in 10 Americans couldn't find work. Today the jobs picture is much better. The unemployment rate is only 4.9%, a level considered at -- or very close to -- full employment.

There are some concerns that the unemployment rate is so low because many people have stopped looking for work out of frustration and are no longer counted in the workforce.

The so-called "labor force participation rate" is at its lowest level since the 1970s. Baby Boomers retiring is causing some of the decline in the work force, but it doesn't explain all of it.