Mark spent considerable time earning the trust of LA's skid row population – a large roadside tent community – and has a series of 1:1 interviews with a slice of the population, exploring their histories, challenges, preferences, and culture.
Mark doesn't believe that many (most?) of the skid row population would benefit from being provided with housing, and that issues of trauma, mental health, and childhood family environment are what he believes would have the highest leverage on the problem.
This is of course just one perspective on the problem, but Mark's perspective taught me quite a bit.