This article draws on other papers in the special issue and additional literature to offer a multi-level framework for understanding the causes of homelessness in the developed world and efforts to reduce or end it. Social policies that reduce inequality and provide income and other supports to those at the bottom of the income distribution are associated with lower levels of homelessness across nations. The allocation of subsidies, patterns of social exclusion, and individual levels of economic, social, and human capital interact to influence who becomes homeless. Interventions to reduce homelessness at one level (e.g., social policy) can counteract vulnerabilities at a different level (e.g., individual risk factors).