Self-employed Americans and the workers they hired accounted for 44 million jobs in 2014, or 30 percent of the national workforce, according to a Pew Research Center analysis of data the U.S. Census Bureau recently made publicly available for the first time.

The self-employed, 14.6 million in all, represented 10% of the nation’s 146 million workers, and they in turn provided jobs for 29.4 million other workers.

While a lot is known about how many self-employed workers there are, far less is known about how many jobs they create. The Pew report attempts to fill that gap. The question is of particular interest to policymakers who have an increasing interest in entrepreneurship. Most entrepreneurs are self-employed.

Not all self-employed workers are job creators, however. Only about one-in-four of them (3.4 million) said they usually have at least one paid employee. Hiring is typically small-scale. Self-employed workers with employees had a median of three paid employees in 2014 and an average of 8.6 employees.

There are significant differences in self-employment and hiring across demographic groups. Asian Americans, one-in-ten of whom are self-employed, lead other groups in the rate at which they hire workers.

Men were nearly twice as likely as women to be self-employed, 12% versus 7%; were much more likely to have paid employees, by 28% to 16%; and, when they hired workers, typically hired more of them.

Hiring varies widely by type of business

Hiring by self-employed workers varies markedly by the type of business they operate. Most job creation by the self-employed—22.5 million out of 29.4 million—flowed from those with incorporated businesses. While most self-employed workers owned unincorporated businesses, those with incorporated businesses were three times as likely to employ others for pay, by 41 percent to 13 percent. And among self-employed workers with paid employees, those with incorporated businesses hired more workers, on average, than the unincorporated (10.2 versus 5.6 workers).

There are some signs of some idling in this job creation engine.

The share of American workers who are self-employed has decreased, from 12.2 percent in 1994, the most recent peak, to 10 percent in 2014. On the other hand, the number of incorporated businesses rose from 2.9 percent in 1990 to 3.7 percent in 2014.

There has also been a decline in the share of self-employed who provide jobs. In 1995, 21 percent reported having at least one employee. That fell to 13 percent in 2014. The share of the self-employed who own incorporated businesses and have paid employees is also down, from about 60 percent in 2001 to 41 percent now.

The Pew research also found that hiring by the self-employed in concentrated in the hands of a few relatively large employers with payrolls of 20 or more. Of the 29.4 million jobs created by the self-employed, fully 16.3 million, or 55 percent, were provided by just 391,000 people. These top-tier employers—11 percednt of all the self-employed with paid workers—each hired 42 workers, on average.

For the full Pew Research report, which includes demographic breakdowns of the self-employed and who is likely to hire paid employees see: