Who is responsible for what

Statistics, regulation, enforcement and policy sit in different places, which is why no single body can answer most questions about disability in the UK.

The landscape of responsibility

Disability figures in the UK do not flow from a single authority. The Office for National Statistics (ONS) produces headline estimates from continuous household surveys and publishes the decennial census results; the Department for Work and Pensions (DWP) publishes data drawn from its own administrative systems — caseloads, assessment outcomes, benefit flows. These are distinct instruments measuring related but non-identical things, and neither body speaks for the other's numbers.

The UK Statistics Authority (UKSA) sits above the production layer as the independent regulatory body. Through its executive arm, the Office for Statistics Regulation (OSR), it designates outputs as National Statistics, assesses compliance with the Code of Practice for Statistics, and can and does publicly challenge government departments when figures are used in ways that mislead. Designation as a National Statistic is a statement about how data were produced and presented, not a guarantee that the underlying concepts are unambiguous. What the OSR cannot do is compel a department to ask a different survey question or adopt a different definition.

Definition itself is partly a legislative matter. The Equality Act 2010 establishes the legal threshold for disability in England, Scotland and Wales; the equivalent in Northern Ireland remains the Disability Discrimination Act 1995. Neither statute was drafted to produce countable survey populations — they were drafted to confer legal protection. The Equality and Human Rights Commission (EHRC) enforces the Equality Act, monitors compliance and publishes its own evidence on equality outcomes, but it does not set survey methodology. The EHRC can report that a gap persists; it cannot close that gap by redesigning a questionnaire.

Where policy sits

Policy on disability employment, benefits and assessment sits primarily with DWP. The department commissions and publishes research, commissions and funds research on health and disability, and is responsible for the Work Capability Assessment and its successors. When the assessment criteria change, the administrative population counted as having a particular award changes — without any change in the underlying condition of the people being assessed. That is a governance decision with statistical consequences, and it is taken by ministers, not statisticians.

The devolved administrations add a further layer. The Scottish Government, Welsh Government and the Northern Ireland Executive each publish their own labour market and health data, and Scotland has begun administering some disability-related benefits directly through Social Security Scotland. Figures produced in Edinburgh and figures produced in London rest on different samples, sometimes different questions, and occasionally different definitions of the same concept. A UK headline assembled from four administrations is an aggregation, and the seams show when you look closely.

NHS England, NHS Scotland, NHS Wales and the equivalent Northern Ireland body generate health administrative data that intersects with disability counts — hospital episode statistics, GP registration data, prescription volumes — but these are not disability surveys. They are clinical records repurposed as population intelligence, and the conversion involves assumptions that vary by dataset.

The gap between what each body holds

No single institution holds the legal definition, the survey methodology, the assessment criteria and the enforcement powers simultaneously. A question about how many disabled people are employed must be answered by ONS survey data. A question about whether an employer has breached the Equality Act must go to the EHRC or, ultimately, an employment tribunal. A question about whether a benefits caseload figure has been presented correctly is for the OSR. A question about whether the assessment threshold is set at the right level is a matter for Parliament and ministers. Select committees are often the forum where these threads are pulled together in public — witnesses from different bodies appear before the same panel — but committees scrutinise rather than decide.

The result is a system in which each body is genuinely responsible for its own piece, and no body is responsible for the whole. Readers who want to understand a single published figure need to know which instrument produced it, which body governs that instrument, and which other bodies' decisions have shaped what the instrument can see.