I have no idea how the census functioned in LA but in NYC the authorities pulled out the stops to maximize participation. They did not want a repeat of the massive undercount of 1990 since population determines both funding and political power.
But the point really isn't whether or not our poor are living better than in poor or middle income countries. The US is a very wealthy nation and should easily be able to minimize abject poverty. Its failure has been dramatically illustrated in New Orleans.
Finally just a quick illustration of what upper middle class life is like in Poland, based on some relatives of mine in Krakow who earn about 25,000-30,000 per year pre-tax: Two parents, two children, modern three bedroom apartment, two cars. TV, computer, regular vacations, good education. So far so good. But... that three bedroom apartment is seventy square meters meaning that the bedrooms are about the size of a full sized bed. The cars are both bottom end sub-compacts, one a few years old, the other ancient. Vacations are to relatives who happen to live in a nice rural lake district. The kids occasionally get a trip abroad for language learning. The parents never vacation abroad (remember that in Europe a vacation abroad is a much more normal thing than in the US). Going out is a rare luxury. And these are people whose standard of living is well above the average for Poland where the average gross salary is, IIRC, about 600/month.
And we do indeed have a significant population living this way. It's hard to admit when it's here in the richest nation on earth, but it is true. Go to any major city to the bad parts of town and look under the bridges and overpasses -- you'll find camps and whole families. Barefoot children and malnourished babies.
Look inside the condemned buildings and you'll find the packs of feral teenagers. Look at the faces of the boys and girls selling their bodies on the streets, if they still look presentable enough. This all seems very third world to me, even though the backdrop is different.
But maybe there's a component of this discussion I'm missing. Maybe we can eventually make language a complete impediment to understanding. -Hobbes
I think we seem to be talking about two different things. If what you're saying is that the bottom one or two percent of Americans live at the level of the bottom half of a rich third world country like Brazil or bottom four fifths of a poor one like India - ok. What I was talking about was the people in the tenth or twentieth percentile - and their lives, while very bad by rich country standards, are quite different. And with the important exception of health care access the lives of the bottom one or two percent are pretty miserable in most European countries as well.