Global Practices and Government Leadership in Data Collection
The UN resolution adopted by the General Assembly in 2021 “calls upon Member States to collect disaggregated data on demographics related to homelessness and establish categories of homelessness, accompanying the existing measurement tools, and encourages Member States to harmonize the measurement and collection of data on homelessness to enable national and global policymaking.”
As the United Nations emphasizes, governments play a vital role in collecting data on homelessness. However, the IGH Global Homeless Data Map shows that only 78 countries currently have official government data, and just 57 have reported data since 2018. Expanding the number of governments engaging in enumeration would greatly improve our understanding of the scale of homelessness worldwide.
That said, collecting reliable data requires the use of consistent, recommended methodologies. In some cases, official government figures have conflicted with estimates from NGOs, researchers, or media sources; thus, highlighting the importance of transparency and methodological rigor. Additionally, the majority of the OECD countries and members of the European Union collect data on people living on the streets or staying in temporary accommodation, but a small number enumerate people living in “non-conventional dwellings” or staying with other households (OECD, 2025). The IGH Global Homeless Data Map shows that a similar situation exists in other regions of the world.
Recognizing that countries vary in context and available resources, this collection presents a range of internationally recognized methodologies and best practices for collecting homelessness data. It also includes examples from cities and countries around the world, offering practical insights and lessons that can support the development of effective, actionable strategies.
The Importance of Homeless Data
Though it manifests in different forms, homelessness is a global phenomenon that affects every country and community. The magnitude of the problem, however, is unknown. In many nations, the absence of reliable and up-to-date data hinders both national and international strategies to address the crisis effectively. Furthermore, this data gap poses a significant barrier to global progress toward ending homelessness.
The OECD Monitoring Framework to Measure Homelessness, published in 2025, recognizes that there are “systemic limitations to homelessness statistics,” which affects the quality and comparability of data across nations. According to the report, one of the factors identified in this methodological challenge is the existence of multiple and inconsistent definitions of homelessness. Currently, there is no universally accepted definition of homelessness.
While The United Nations 17 Sustainable Development Goals exclude homelessness, efforts should be made to enhance homeless data through clear, standardized, and inclusive definitions and consistent methodologies. Moreover, enumeration processes must be carried out regularly and apply recommended practices.
Without this foundation, efforts to reduce homelessness risk being fragmented, incomplete, or ineffective.
Ensuring Data Quality and Integrity
Maintaining high data quality is essential regardless of the enumeration method used to count people experiencing homelessness. This begins with data validation and cleaning to identify and correct possible inconsistencies. Equally important is the proper training of enumerators and field teams, ensuring they understand the methodology and engage respectfully with participants.
Ongoing monitoring for bias and data gaps helps maintain accuracy and fairness throughout the process. Finally, adopting standardized reporting formats guarantees that results are transparent, comparable, and easily understood by all stakeholders.
Throughout the entire process, people experiencing homelessness should be recognized as essential contributors, actively involved in designing and implementing enumeration strategies. Their voices and lived experiences bring valuable insights that enhance the process.
Aligning Purpose, Capacity, and Context
Choosing the most appropriate method to collect data on homelessness depends on several key factors, including the specific goals of data collection, the local context, and the capacity of institutions involved. Depending on the objective, government agencies should consider that:
- If the aim is to generate an estimate to inform immediate service delivery, a street count or service-based enumeration may be suitable.
- For tracking long-term trends or assessing policy effectiveness, methods like administrative data, homeless household applications, and capture-recapture offer continuity and a more in-depth examination of the state of homelessness.
- Cities with high rates of informal settlements could utilize surveys or community-based data collection to understand the hidden homeless population.
- Areas with a robust social protection network may benefit from leveraging service data for more accurate estimates.
Resources and capacity will further influence what is feasible. Some methods require minimal infrastructure but provide only basic snapshots, while others demand more coordination and technical expertise but produce richer, more actionable information.
Ultimately, the decision should be grounded in a clear understanding of what questions need answering, who will use the data, and how the findings will be applied. The most effective approaches often combine multiple methods to balance coverage, reliability, and practicality, tailored to local priorities and realities.
Turning Data into Action
Collecting data on homelessness is essential, but data is only powerful when it is used to drive meaningful change. When current and quality data informs strategies, it enables targeted, effective, and accountable responses at both national and regional levels.
Accurate enumeration provides a critical baseline, helping decision-makers understand the scope and nature of homelessness in their context, allocate resources wisely, design interventions based on specific populations (such as youth, families, or chronically homeless individuals), and monitor emerging trends or geographic shifts over time.
Ongoing data is vital for measuring impact and accountability since collecting data not only before designing a strategy but also during the implementation phase is fundamental to revealing which populations are most underserved or at risk.
Beyond program design, homelessness data plays a key role in advocacy and systems change. It strengthens the case for policy reform, raises public awareness, and can help unlock funding. Used effectively, data becomes a tool not just for understanding homelessness, but for driving real, measurable progress toward ending it.
Defining Homelessness
Since the Institute of Global Homelessness (IGH) advocates for an inclusive definition of homelessness, we developed a global typology, which offers a common language to support cross-country collaboration. This framework considers:
- People without accommodation.
- People living in temporary or crisis shelters.
- People living in inadequate and insecure housing.
Defining homelessness is an important step in determining what enumeration methods might be most effective for your community. At a global level, consistent definitions would contribute to comparing strategies and outcomes across different national contexts.
Data Collection Methodologies
Street Count
A Street Count offers a snapshot of homelessness by estimating the number of people experiencing homelessness in a specific area on a single night. While a Street Count or Point-in-Time (PIT) typically includes a basic headcount, it can also gather demographic details.
Administrative Data
Administrative data refers to information collected by service providers or government agencies as part of their regular operations. This data includes details about the services delivered and information about the individuals they assist.
Census
The census method is an official count or survey of a population used to gather demographic data and historical housing information. It is often conducted as part of a broader effort to enumerate both the population and housing conditions.
By-Name List
A By-Name List helps prioritize housing and support services based on individual needs. The data can be collected through a Registry Week, a coordinated process used to collect detailed information about every person and family experiencing homelessness in a community.
Additional Approaches
This section includes a description of other methodologies that could be used to measure homelessness, including the Capture-Recapture method, Homeless Applications, Surveys, and Service-Requests.
Global Homeless Data Map
The IGH Global Homeless Data Map provides a snapshot of the state of homelessness data and emphasizes the need for improved data quality and consistent definitions.