Abstract for: A Virtual Lab for Homelessness Policy in the UK: Using System Dynamics to Design and Test Intervention Strategies

The present project represents a collaboration between Centre for Homelessness Impact (CHI), a nonprofit research firm based in London, and homelessness researchers with system dynamics expertise from the United States to identify barriers to efficient service provision and potential leverage points to reduce homelessness in the current policy environment using system dynamics simulations. A stock-and-flow structure models homelessness in England drawing upon prior empirical research, theory, and consultation with homelessness experts. The model is adapted from a previously published model of homeless service use (Fowler et al., 2019; Marçal et al., 2021, 2023) and incorporates insights from system mapping with providers and advocates undertaken as part of an ongoing System-wide Evaluation and broader insights on urban dynamics (Forrester, 1969; Ghaffarzadegan et al., 2011). Results suggested the optimal intervention strategy involved a 26% improvement in the efficacy of relief duty, by which clients stabilize from short-term assistance before being offered temporary accommodation, and a 10% increase in efficacy of inadequate temporary accommodation, whereby clients are quickly moved into adequate accommodations. The simulation replicates observed patterns of homelessness. Modeling demonstrates sufficient credibility for policy testing. Future work will engage stakeholders in identifying additional policy levers for testing aligned to topics chosen for phase 2 of the Systems-wide Evaluation. For instance, the model is calibrated to test whether various legislative or programmatic interventions to support financial security sustainably reduce entries into homelessness and rough sleeping in the context of national economic shifts.