The many different kinds of homeless people become homeless in many different ways. It is obvious that people become literally homeless because they are extremely poor and cannot successfully compete for a dwindling supply of low-income housing. Literal homelessness is a function of extreme poverty in a housing market that has an inadequate supply of very low-cost housing to offer, especially to single individuals. One may either lose or reject the resources otherwise available in the social network; either path to homelessness is open. There is little doubt that the destruction of social support networks characteristic of most homeless people is in its turn strongly related to their high levels of personal disability. The proportional burden of taking on the support of an additional adult, that is, would be relatively high, and the line of defense against literal homelessness correspondingly thin.