The importance and challenges of using natural experiments to evaluate the health effects of housing policy. A commentary on Schwartz and Chu's "Do laws protecting tenants' health work?: Implied warranties of habitability and respiratory health".

Housing policy remains underutilized as a lever for better population health. This commentary discusses the intersection of housing policy and population health, focusing on the use of natural experiments to evaluate the health effects of housing policies. We consider Schwartz and Chu's paper (Am J Epidemiol. XXXX;XXX(XX):XXXX-XXXX)) in which they employ a natural experiment approach to quantifying health impacts of habitability warrants: state-based housing policy aimed at protecting renters in the US. The paper's null findings highlight the complexities of evaluating health effects of housing policies. Findings could be explained by policy failure i.e., habitability warranties place the burden on tenants to act, requiring them to invest resources and potentially risk their tenancy to address suboptimal living conditions. Methodological challenges could also contribute including limited sample sizes, reliance on self-reported data, and potential confounding factors. We argue that failure to optimize housing policies for health outcomes leads to missed opportunities to improve population health using prevention strategies, potential widening existing health inequalities. This review underscores the need for continued research into the health impacts of housing policies, advocating for a shift towards health-centric policy evaluation to better leverage housing as a key social determinant of health.