A high proportion of rent-to-income is a key contributor to homelessness. People who find that rent eats up so much of their income that they can’t afford other necessities will often try their luck doubling up with relatives or friends or temporarily using a city’s shelter system. Anything that influences the rent-to-income ratio from income support programs to tax policies affecting the costs of new construction and the costs of maintaining or rehabilitating old buildings, to zoning and density restrictions will therefore have a significant influence on the rate of homelessness. Recognizing this opens a wide range of policy options and exposes all levels of government to the responsibility for initiating useful policy reforms.