The Sutton Trust’s Opportunity Index 2025 places London in a category of its own. The capital occupies the overwhelming majority of the highest-ranked constituencies for social mobility, even when levels of deprivation are taken into account. At first glance, this seems to confirm a familiar story. London has stronger schools, better labour markets, more universities, and greater institutional capacity. All of these factors matter. Yet they do not fully explain why London performs so exceptionally when disadvantage is measured using Free School Meal eligibility, the core indicator underpinning the Opportunity Index.

To understand London’s apparent advantage, it is necessary to look beyond outcomes alone and examine how disadvantage is identified, recorded, and acted upon.

London’s educational context

London’s improvement in educational performance is well documented. The London Challenge, launched in the early 2000s, marked a decisive shift in how schools were supported and held accountable. Investment in leadership development, collaboration between schools, and targeted intervention in underperforming areas contributed to rapid improvements in attainment, particularly at secondary level. By the end of the programme, London had moved from being one of the weakest regions educationally to one of the strongest.

The capital has also benefited from its ability to attract teaching talent. Higher wages, career opportunities, and the concentration of training programmes such as Teach First have helped channel early-career teachers into disadvantaged schools. London’s dense transport network and school choice landscape further widen access to high-performing institutions and post-16 pathways.

Demographic change has played a role as well. Gentrification has altered school intakes in many boroughs, while immigration has increased diversity. However, research consistently shows that London’s advantage persists even when controlling for ethnicity and background. White pupils in London also outperform their peers elsewhere, indicating that demographics alone cannot explain the scale of the gap.

The London effect as context dependent

To establish that London’s stronger outcomes for disadvantaged pupils are not simply a statistical artefact of population composition, it is necessary to look at the literature on the so-called London effect. A major literature review by Macdougall and Lupton (2018) synthesises evidence showing that London’s comparative advantage cannot be explained by demographic composition alone. Instead, the review identifies institutional factors, including school improvement programmes, patterns of resource allocation, and local authority leadership, as central to understanding London’s performance.

Importantly, the authors frame the London effect as context dependent rather than merely demographic. This means that pupils from similar backgrounds tend to achieve better outcomes in London because of the institutional and policy environment in which they are educated, not simply because of who they are. The relevance of this finding is not that London has eliminated disadvantage or reduced structural barriers, but that place-based systems shape how disadvantage is addressed and translated into outcomes.

Free School Meals as an administrative measure

The Opportunity Index measures social mobility using outcomes for pupils who were eligible for Free School Meals at age 16. FSM is a widely used proxy for disadvantage and remains essential for identifying pupils who require additional support. However, FSM is not a direct measure of poverty. It is an administrative status shaped by eligibility thresholds, registration processes, and institutional practice.

Research from the Education Policy Institute and the Nuffield Foundation shows that eligibility for Free School Meals and the likelihood of being registered vary substantially by place and over time. This means that children with similar levels of underlying poverty are not equally likely to be recorded as FSM eligible in different regions. Yet in analyses of social mobility, FSM status is often treated as a fixed and comparable marker of disadvantage. When registration depends on local administrative practices and institutional capacity, this assumption breaks down. As a result, comparisons of outcomes between FSM pupils across regions risk conflating differences in opportunity with differences in how disadvantage is identified and recorded.

How FSM operates differently in London

In London, FSM administration is routinised. Schools deal with large FSM cohorts and have established processes for identifying eligible pupils. Local authorities are more likely to conduct periodic eligibility checks and support schools in registering families. Interaction with public institutions is common across income groups, making registration a routine administrative step rather than an exceptional act.

By contrast, in many non-London areas, FSM registration relies more heavily on parents initiating applications and navigating systems themselves. Schools often work with smaller FSM populations and have less administrative capacity dedicated to entitlement identification. In these contexts, FSM status is more likely to capture a narrower group of pupils experiencing persistent disadvantage.

This difference does not imply that London is less deprived. London has high child poverty rates. Instead, it suggests that FSM registration reflects different mixes of circumstances across places, shaped by income volatility, residential mobility, and administrative practice.

Universal provision and reduced friction

Recent policy decisions have further altered how FSM functions in London. Since 2023, all state primary school pupils in London have been offered free school meals through mayoral funding. This universal provision does not remove the need for means-tested FSM registration for funding purposes, but it decouples meal access from eligibility.

As a result, schools can encourage registration by framing it as a mechanism to secure resources rather than a condition for receiving food. This reduces stigma and administrative burden, while allowing local authorities to identify eligible pupils more effectively. The consequence is both substantive and methodological. More children receive support, and FSM data more accurately reflects the population entitled to additional resources.

What London’s advantage really shows

London’s position at the top of the Opportunity Index does reflect genuine strengths in schooling, labour markets, and institutional capacity. But it also reflects something more fundamental. London is better at finding disadvantage and acting on it.

FSM remains an essential indicator. Without it, disadvantage becomes invisible to policy. But the London case shows that how FSM is administered shapes who is counted, who receives support, and how opportunity is ultimately measured.

If London’s success tells us anything, it is that social mobility begins with identification. Reducing administrative friction, routinising support, and separating help from stigma do not just improve lives. They also change what our data shows us about who is being left behind.

In that sense, London’s real advantage is not that it has solved disadvantage, but that it has built systems that are better at seeing it.