Homelessness is a serious social problem that is unlikely to be solved by grand proclamations or a single policy initiative. It is, more likely, to be solved by the introduction of innumerable changes both in how we understand the problem and how we approach its solution. In this paper we examine the costs and benefits of tax measures that would promote greater involvement of the private sector in the provision of affordable housing. We also examine the costs and benefits of a variety of regulatory initiatives. In an earlier era, centrally directed federal-provincial grant programs for housing run by governments and non-profit organizations were the means of providing affordable housing. Most of the proposals in this paper, in contrast, aim to harness the energy and the efficiency-promoting competition of the private sector. The focus is on decentralized decision-making. Some measures would depend heavily on individual entrepreneurs and non-profit organizations. Others would depend on municipal governments, whose program capacities have grown greatly in recent decades and whose closeness to their constituencies makes them well-placed both to develop and to deliver supportive measures. Our assessment of possibilities suggests that a low-income housing tax credit best balances effectiveness with the need to minimize costs on strained government budgets. Tax measures aimed at investors in multi-unit rental buildings are also likely to meet these criteria