There are more available jobs in the United States today than there have been since records started being kept in 2000.

But only 62.6% of American adults are looking for a job or already working.

It's a puzzling situation, one which economists and labor statisticians are just beginning to tease out.

Baby Boomers are retiring, women aren't as active in the workforce as they once were, young people are staying in school, and immigrants don't feel welcome in many positions.

June's low 5.3% unemployment rate didn't take into account the 94 million Americans who simply aren't working, nor the 640,000 who left the workforce for good in May. Back in 2000, American civilian labor participation peaked in 2000 at 67.3%, far higher than it had been in previous decades. The recent dropoff has, however, accelerated in the past couple of years.

Some attribute this to potential retirees being forced to continue working following the recession, only now becoming financially stable enough to leave the workforce for good. But prime age workers (those 25-54 years of age) have dropped out at similar rates.

It's a complex issue, and one which economists don't expect to see turn around anytime soon. But suffice to say, it's a job-hunter's market in the United States.

Read full article at US News and World Report.