There seems to be a pretty sharp lower bound on how cheap a living situation (e.g. rent on an apartment) can be in the parts of the United States I'm familiar with. I would have thought that there would be demand for cheap-but-bad housing on the part of people with low income. Here are some hypotheses I've come up with for explaining this, and I'd appreciate anyone who has relevant knowledge commenting if I'm on track:

• There is in fact very little such demand in the US because people who can afford any kind of rent at all have grown accustomed to a certain standard of living.
• The cost of complying with health and safety regulations makes it too expensive to price rent below a certain amount even at the worst the rental situation is legally allowed to be.
• The people who would try to rent as cheaply as possible are also the people who are least likely to pay their rent (e.g. due to job insecurity), and landlords don't want to take on the additional risk.