(Photo by Kevork Djansezian/Getty Images)

We often make assumptions about people on public assistance, about the woman in the checkout line with an EBT card, or the family who lives in public housing. We make assumptions about how they spend their resources (irresponsibly?), how they came to rely on aid (lack of hard work?), how they view their own public dependence (as a free ride rather than a humbling one?).

We assume, at our most skeptical, that poor people need help above all because they haven't tried to help themselves — they haven't bothered to find work.

The reality, though, is that a tremendous share of people who rely on government programs designed for the poor in fact work — they just don't make enough at it to cover their basic living expenses. According to the UC Berkeley Center for Labor Research and Education, 73 percent of people who benefit from major public assistance programs in the U.S. live in a working family where at least one adult earns the household some money.

The problem, according to this picture, isn't that poor people won't work — it's that the work they do can't sustain them. The problem is that more than half of people who work on the front lines of fast food, and nearly half of child-care workers and home health aids, still need government help buying their groceries or covering their medical bills after they get their paychecks.

Share of workers receiving public assistance for the poor, by industry

Share of workers in each field who rely on at least one program among Medicaid/CHIP, TANF, the EITC or food stamps. UC Berkeley Center for Labor Research and Education

That chart, from a new research brief by Ken Jacobs, Ian Perry, and Jenifer MacGillvary at Berkeley, shows the share of workers in each field who also rely on at least one of four major government programs for the poor: food stamps (SNAP), Medicaid or the Children's Health Insurance Program, the Earned Income Tax Credit, or income supports through welfare (the Temporary Assistance for Needy Families program).

This picture casts the culprit in a different light: Taxpayers are spending a lot of money subsidizing not people who won't work, but industries that don't pay their workers a living wage. Through these four programs alone, federal and state governments spend about $150 billion a year aiding working families, according to the analysis (the authors define people who are working here as those who worked at least 10 hours a week, at least half the year).

This is true of more than half of people on Medicaid, and a third of families on food stamps:

This data may be its own Rorschach test: Maybe you look at it and see not the third of families on welfare who work, but the two-thirds who don't for various reasons. But the important point here is that it is quite possible to work hard in this country and still need help buying dinner — a fact that says more about the nature of work in America than a shortage of work ethic.