People experiencing homelessness in the U.S. face a wide range of challenges related to their housing situation, including mental health issues and addiction. Policy debates over homelessness are often fraught with stigma, prejudice, politics, and ultimately it seems that little progress is made. When we look past our assumptions, what does the data say about how to solve the housing crisis? It’s hard to measure, and there are many variables at play. But one researcher at New York University is studying ways to prove the effectiveness of solutions like housing vouchers and assistance programs.