You only need to take a quick look at the Centre for Homelessness Impact’s Evidence Finder to notice the contrast between the types of homelessness studies produced in the UK and the US. While in the US, a large volume of quantitative ‘impact’ studies on homelessness has been generated over many years, homelessness researchers in the UK have tended to be concerned with more qualitative and conceptual forms of exploration and evaluation. 

This has profound implications for our ability to answer pressing policy and practice questions, which often require mixed methods approaches that attain both breadth and depth of understanding. This contrast between the US and UK homelessness literature can be traced back to the different research traditions that have emerged over the years on opposite sides of the Atlantic.

Regardless of any country’s research traditions, a wide range of disciplinary perspectives have valid contributions to make in tackling homelessness, and more extensive engagement between scholars across the developed world in recent years has enriched our respective research traditions. One benefit of this international engagement has been to draw out ever more clearly the importance of striking a balance in research efforts such that we are able to stand back and identify the fundamental drivers of homelessness while simultaneously engaging in robust evaluation of targeted, practical responses that seek to prevent or alleviate homelessness in the here and now. This balance requires attention to both the macro and the micro scale, and to both qualitative and quantitative methods of analysis.

What unites and divides the UK and US

In the UK, a preoccupation with more theoretical and political concerns on homelessness has meant a relative neglect of robust evaluative research on targeted interventions. Such micro-level initiatives proliferate in the UK homelessness sector, but very few have undergone rigorous evaluation, with cost–benefit analysis and other quantitative techniques a particular rarity. Given the 80 percent rule – that most interventions, when scrutinised closely, turn out to be ineffective – this should be a serious matter of concern.

In the US, conversely, the emphasis on quantitative impact evaluation has a tendency to limit the survival and proliferation of ineffective or financially inefficient programmes. Politicians and philanthropists alike boast about cost savings and return on investment, and often require that grantees maintain an administrative database that allows the programme to report on use and conduct an outcome evaluation that is likely to include some measure of cost–benefit analysis. While this may sound positive, an often myopic focus on outcomes and performance metrics can overshadow qualitative research that offers extensive depth into the experience of the lives and service needs of those experiencing homelessness.

Despite these strong contrasts between the UK and US research and policy traditions and priorities, it is clear that there are also some common priorities and opportunities for future development, many of which are shared by other developed nations. For example, while there is widespread agreement that “prevention is better than cure” with respect to homelessness, most countries across the developed world struggle to turn this aspiration into reality.

A lack of credible evidence and data to focus preventative efforts is a major part of the problem. The sort of statistical and forecasting evidence that is now developing in the UK is especially important in developing tools for more universal or ‘upstream' forms of homelessness prevention to identify the welfare, housing and other structural levers that must be activated to lower overall population-level risks. But policymakers in the UK and US have both struggled to drive resources upstream.

International evaluations and comparative research also have a potentially major role to play in identifying the policy and structural factors that drive homelessness, particularly at national level. Systematic cross-national research is all too rare in the homelessness sector.

Another common thread is the potential contribution of administrative data linkage for understanding and addressing the complex, cross-system needs of people who experience homelessness. The US, with its richer history of administrative data linkage in the social service sector, has a head start on its British counterpart. All told, though, researchers, policymakers, and practitioners have been slow to capture the potential for cross-system linkages, as these data-sharing projects are confined to agencies with entrepreneurial leaders.

In the meantime, in the UK, there are myriad as yet unrealised opportunities for administrative data linkage to support longitudinal evaluations of homelessness and related interventions at much lower cost than repeat large-scale surveys — although MHCLG is already leading the way in the field with initiative like the Troubled Families Programme.

The importance of evidence

On both sides of the Atlantic, good evidence is a vital part of ending homelessness for good. One key reason why evidence is so important is to overcome inertia and innovation barriers associated with ‘path dependency’ among existing homelessness policies and services.

In other words, once people, resources and organisations are invested in a particular model of intervention, it is very difficult to change tack, even if there is little sign that the intended outcomes are being achieved.

Good evidence is also vital in dispelling falsehoods such as the idea that any of us can become homeless. While such “inclusive” narratives may appear progressive on the surface, they do serious damage by distracting attention from the structural inequalities that in reality drive homelessness risks.

Finally, both nations should acknowledge the role that systematic reviews and meta-analyses potentially have to offer in the homelessness field, as in so many others, in determining and championing ‘what works’. But the necessary underlying empirical evidence base – which is currently underdeveloped in homelessness – must exist for these synthesising methods to deliver maximum value. Leaving aside Housing First and certain health-specific interventions, quantitative evaluations that would meet the usual ‘gold standard’ evidence thresholds for systematic reviews are rare in the homelessness field outside the US. Thus, investment in more robust primary evaluations needs to be a priority in the UK and elsewhere.

It is clear that the UK and US already have much common ground to build on, but many challenges ahead — with some of these challenges apparent on both sides of the Atlantic. But we must not lose sight of the importance of evidence in shaping the way forward in improving homelessness prevention and alleviation.‍

Suzanne Fitzpatrick is Professor of Housing and Social Policy in the Institute for Social Policy, Housing, Environment and Real Estate (I-SPHERE), Heriot-Watt University

Dennis Culhane is Professor of Social Policy and Practice at the University of Pennsylvania