Housing affordability: a framing, synthesis of research and policy, and future directions

We synthesize the vast, international scholarly literature related to the growing problem of housing affordability. As a foundation for assessing both the causes of housing affordability problems and possible policies for alleviating them, we take a systematic, holistic perspective and specify nine structural relationships for a metropolitan area that comprehensively delineate the determinants of housing affordability. We discuss concepts and measures of housing affordability, evidence on the primary causes and effects of unaffordable housing, alternative policy approaches, potential future trends in affordability, and suggestions for further research. While focusing on the most recent, high-quality empirical evidence, we also rely on previously published reviews and seminal papers in order to provide historical perspective on how the literature has evolved. Our reconnaissance of the international literature since 2008 demonstrates that although evaluation research in the context of western, developed countries' housing policies has dominated, increasingly such research has emerged from other countries.