"People need to recognize we are all contingent workers in one form or another," he said.

Toledo is home to glass and automobile companies which, while shrinking, are unionized and make little use of contingent workers.

Other numbers reflecting the growth of contingent workers are still murkier.

But with industry relying on contingent workers, who might provide those better jobs is uncertain.

Somewhat fewer contingent workers, however, have high school diplomas.

The proportion of contingent workers with health insurance from any source ranged from 57 to 65 percent, the study found.

Over all, the ranks of contingent workers were estimated to range from 2.7 million to 6 million workers.

For example, a plan can exclude contingent workers or workers hired through a third party agency.

These are service jobs, contingent workers without benefits and significantly lower pay scales.

In many cases, such as the 32 million unorganized contingent workers, the work is scattered, making traditional organizing difficult.