As of 2024, over two million people were estimated to be experiencing homelessness each year in OECD and EU countries. As a range of methodological challenges complicate the measurement of the extent of homelessness, it is hard for policymakers to develop evidence-based policy solutions. This paper discusses measurement challenges and aims to address them by advancing understanding, assessment and comparison of homelessness in OECD and EU countries. Section 1 summarises the main methodological challenges to measurement and cross-national comparison of homelessness indicators and presents the scope of the existing statistical definitions in OECD and EU countries. Section 2 presents the six most common approaches to collecting data on homelessness, as well as their strengths and limitations. It also highlights different socio-demographic groups that are often underreported or “missed” in standard data collection exercises, and the methodological challenges behind this evidence gap. Section 3 proposes a self-assessment tool to help strengthen data collection and features some relevant practical examples.
