Homelessness is a complex problem that requires analysis tools designed for complex systems. One of these tools is a ‘stock and flow’ analysis. Many communities in Canada have an idea of the number of people presently experiencing homeless, estimated by point-in-time counts or the stock of homeless people. In most areas, relatively little is known about flows into and out of homelessness.

This chapter uses stock and flow analysis to present a comprehensive model of chronic homelessness. Using Edmonton as a case study, it identifies what data are required to capture different aspects of inflow, outflow and stock. It then presents a partially calibrated model of the stock and flows of people into and out of the chronically homeless population and details what information is required to develop an estimate of the rate at which homeless people need to be housed in order to end homelessness.