It seems the causation is not (drunk OR crazy) => homeless but more homeless => (drunk OR crazy). The fundamental attribution error says that to explain a behavior, we frequently overlook situational explanations (upbringing, environment) to favor dispositional explanations(character, identity) http://en.wikipedia.org/wiki/Fundamental_attribution_error. Same reason why immigrants cause problems, it's not because of them being immigrants but of them living in hard conditions.
I made no claims concerning causality. I only made a factual claim that "most homeless are crazy" and inferred that as a result they would be "are unlikely to accept your advice" (to make more money).
If you have evidence as to the direction of causality, feel free to post it.
My comment was to be read in the context of the discussion, as in, it's not as simple as to tell to homeless people to go "develop their moneymaking skills" and it's not simple because of a myriad of factors, not because they're crazy and drunk (consequence of their situation).
I don't have direct evidence of the causality other than the comment I've posted above.
