Luke Stanley is Policy Adviser to Lord Hague of Richmond and Senior Parliamentary Researcher to Anthony Mangnall MP. He writes in a personal capacity.

“How did this person end up sleeping on the street?” is a question that most of us will have asked ourselves at some point in our lives, walking past homeless people bedding down for the night. While it seems a straightforward question, the underlying factors that result in someone sleeping rough are anything but.

Boris Johnson’s One Nation Conservative Government is making encouraging progress in supporting rough sleepers to rebuild their lives, with street counts down three years in a row.

Their landmark Rough Sleeping Initiative, which funds accommodation and health services for rough sleepers, has been found to reduce rough sleeping by one-third and received a £200 million boost earlier this month.

But if we want to end rough sleeping for good, we need to do more than support existing rough sleepers. We also need to prevent vulnerable people from ever reaching the streets.

Writing for this website last year, Robert Jenrick, the Housing Secretary, rightly described rough sleeping as being “as much a health issue as it is a housing issue”. As with most health issues, the conditions that can eventually result in rough sleeping are far easier to treat, but much harder to detect, in their early stages.

Ramping up early interventions to prevent rough sleeping will require a forensic understanding of the long-term process by which a vulnerable person ends up on the street, a depth of knowledge our society currently lacks.

Existing research suggests there are two broad groups of factors that can contribute to rough sleeping.

First, there are structural problems in our society, such as levels of affordable housing and insecure tenancies. Second, there are individual problems that make certain people more likely to end up on the streets, like poor mental health, addiction, and relationship breakdown.

These often fuel one another, for example, untreated mental health problems fuelling addiction, resulting in vicious cycles that leave people with broken lives, unable to hold down a home.

To try and get a deeper understanding of this issue, the May Government commissioned a Rapid Evidence Assessment of research into the causes of homelessness and rough sleeping. This agreed that both structural and individual problems were factors, but that the latter played a larger role in explaining rough sleeping than it did in other forms of homelessness.

That general conclusion aside, the report highlighted a number of gaps in the evidence base.

First, there is a lack of robust data on the immediate causes of rough sleeping. The report noted that much of the third-party research in this area uses simplistic surveys which have limited use for informed policy making. For example, one such survey had “Asked to leave or evicted” as the top reason for rough sleeping, but sought no information on the context behind this. A greedy landlord increased rent; someone with mental health problems was unable to hold down a job; a gay person was rejected by their bigoted family. Three wildly different scenarios, each of which would be captured as the same by this survey.

Second, and more crucially, there is a lack of evidence on the long-term causes of rough sleeping. As discussed above, many of the individual problems linked to rough sleeping exacerbate one another. Understanding this process is key to improving early interventions and preventing people from becoming rough sleepers.

Ultimately, we can build as many houses as we want, and introduce as many restrictions on landlords as we please, but until we’ve untangled the causes of the chaotic lifestyles that drive vulnerable people onto the streets, we will never end rough sleeping.

This can be achieved through more qualitative ‘pathway’ studies, which seek to map individuals’ journeys into rough sleeping. As the report noted, pathway studies are especially important for designing preventative policies but many use small samples, limiting their usefulness. In their words, more pathway studies, with larger samples, would help us “further understand both interactions between causes and the order of events that can lead to homelessness”.

Third, we need a better understanding of rough sleeping risks for different demographics. The factors behind rough sleeping are complex and affect different people in different ways, rendering one-size-fits-all approaches unhelpful. To its credit, the Government is already undertaking research to better understand the causes of rough sleeping for one specific demographic: gay and trans people.

But going further, the Government could also consider commissioning research to gather robust evidence to plug the first and second gaps on the causes, both short-term and long-term, of rough sleeping. With their landmark ‘Everyone In’ campaign housing over 26,000 rough sleepers and homeless people at risk of sleeping rough, there is a golden opportunity to explore the causes of rough sleeping. For the first time, we have a large number of people with lived experience of rough sleeping in secure accommodation, where they are far more accessible to researchers.

We should seize this opportunity to better understand how to help vulnerable people, use this to develop stronger preventative interventions, and confine rough sleeping to the history books.