No need to set up an experiment, look outside of the U.S. at Rio de Janero. High rises aplenty for the middle and upper class, and the working class living in favelas straight out of the middle ages but with high voltage power lines. That being said, living in a favela is probably much more comfortable than what we deem acceptable for our economic underclass: living in a tent on the street.
You're drastically exaggerating of course. Unless you're primarily talking about a few cities like Los Angeles and San Francisco. The US has a wildly successful Housing First program that has pushed its homelessness rate below that of France, Germany, Britain, Sweden, Australia, New Zealand. A rate comparable to that of Finland, Netherlands, Austria.
