Huh. Don't know if RH has me set to ignore, but I was curious so I googled a bit more.

Here are some figures from Texas a while ago. Not the most up to date info, but it's got demographical data.
http://www.hhsc.state.tx.us/research.../dempov97.html

Some highlights
41.80% of the people in poverty are under 18
43.68% of the people between 18 and 65 ARE WORKING, and 8.29% are looking.
An unknown percentage of those remaining are watching the kids at home and the like.
10% are over 65.

For the kids in poverty the biggest group are just with a single mother 48.12% though a surprising number have both parents. 41.46%

So kids, people who are working, and people who are retirement age make up 72% of the people in poverty. (and in the remaining 28% are people who are handicapped, caring for the children full time, or those crazy guys we get yelling in the middle of the street.)

So the could work but doesn't crowd, while real, makes up a small minority of the people under the poverty threshold.

Though on the note of that minority

we get some
http://en.wikipedia.org/wiki/Crusties
out where I am, spanging around the public transportation.