58.4%: Percentage of U.S. population employed

Nearly two years into the economic recovery, the U.S. has made troublingly little headway in putting people back to work. If the animal spirits needed to create jobs don’t return, the country could soon be facing a renewed crisis.

Even as private businesses have added hundreds of thousands of jobs, the percentage of the population gainfully employed has hardly budged. As of May, it stood at 58.4%, a percentage point lower than at the bottom of the recession in mid-2009. That compares to a peak of 62.7% in December 2007.

The discrepancy reflects a number of problematic trends. The average rate of job creation in recent months isn’t much more that what’s needed to offset population growth. A lot of people have given up on finding jobs, and so aren’t included in the official count of the unemployed. The aging of the population also means more old folks out of the work force.

This isn’t a problem only for people without jobs. The smaller the share of the population employed, the smaller the economy’s potential to lift living standards through productivity gains. Indeed, productivity — companies’ ability to keep squeezing more production out of each hour worked — is transformed from the prime driver of prosperity into a force keeping people out of work. Profits rise, but the ranks of the unemployed don’t shrink.