In 2011, some 46.2 million Americans lived below the official poverty line — 15 percent of the country. Of those, roughly 10.4 million counted as the "working poor," people who either had jobs or were looking for at least half the year, but still fell below the line.

Those figures come from a new report out by the Bureau of Labor Statistics that tries to get a better picture of the working poor in America. One big finding is that — no surprise — the number of workers in poverty soared during the recession:

The official poverty line is $11,484 for an individual or $23,021 for a family of four. And more and more American workers are falling below that line.

Why is that? The BLS report drew a few broad conclusions:

— Part-time work was much more conducive to poverty than full-time work. Some 14.4 percent of part-time workers fell below the poverty line, compared with just 4.4 percent of full-time workers. The fact that part-time jobs have made up a huge chunk of the U.S. economic recovery has a big effect on poverty rates.

— Low wages are, not surprisingly, the biggest problem. About 66 percent of the working poor fell below the poverty line at least in part because of low earnings. But the still-terrible labor market played a big role too: 39 percent of the working poor experienced bouts of unemployment during the year.

— Some jobs have higher rates of poverty than others. The largest group of working poor were in the service industry — 3.3 million, or 13.1 percent of all service workers. Other jobs with particularly high rates of poverty include farming, fishing, and forestry (17.1 percent) and construction and extraction (10.6 percent).

— Education levels make a huge difference. Just 2.4 percent of college-educated workers fell below the poverty line. By contrast, 9.2 percent of high-school graduates in the labor force were classified as working poor, while 20.1 of those who never finished high school fell below the line.

— There are huge racial disparities. "13.3 percent of Blacks and 12.9 percent of Hispanics were among the working poor, compared with 6.1 percent of Whites."

— There's also this fact about children: "Among families with at least one member in the labor force for 27 weeks or more, those families with children under 18 years old were about 4 times more likely than those without children to live in poverty."

Further reading:

— Sudeep Reddy of Real Time Economics has his own smart breakdown of the BLS report.