Extra cost

Estimates of what disability adds to household expenditure exist, and they disagree substantially — because what is being measured is itself contested.

The measurement problem

Several organisations have published figures estimating how much more disabled people spend, on average, than non-disabled people with equivalent incomes. The numbers vary enough to matter: estimates have ranged from roughly £570 to over £1,000 per month in extra costs, depending on the study, the year and — above all — the method. None of these figures is wrong in the way an arithmetic error is wrong; they are measuring different things.

The central difficulty is that "extra cost" is not a single item in anyone's accounts. It is an aggregate covering mobility aids, specialist food, higher heating bills, adapted transport, paid personal assistance, and a long list of smaller expenditures that vary with condition, severity, household composition and geography. Any estimate must decide which items count, whose costs are included, and what comparison group provides the baseline.

Studies that ask disabled people directly what they spend tend to produce higher figures than those that use expenditure surveys and model the gap statistically. Direct-ask methods capture what respondents attribute to disability; modelled approaches can only measure what appears in the survey instrument, which rarely has a dedicated disability-cost category. Neither method is clean. Recall error and attribution error run in opposite directions and are difficult to separate.

The income side matters as much as the expenditure side. A cost that consumes ten percent of a median income is a different burden at the bottom of the income distribution — and disabled people are overrepresented at lower incomes, which means the same nominal cost is not a comparable hardship across the group.

Severity is rarely handled consistently. A figure averaged across all disabled people flattens the difference between someone with a mild, managed condition and someone requiring round-the-clock care. Disability is defined differently across the sources that feed these estimates: some use the Equality Act definition, some use survey self-report, and some use benefit receipt as a proxy — so the population being averaged is not the same population from study to study.

No official statistical body publishes a regular, designated extra-cost series. The figures in circulation come from research organisations and third-sector bodies, each using their own methodology on their own schedule. That means the numbers cannot be tracked over time in the way that employment or pay gaps can. A figure from one year is not necessarily comparable with a figure from three years earlier, even from the same source, if the method or the population definition has changed between them.

Threshold is an independent publication about disability statistics and governance. It is not an advice, advocacy or support service and does not provide guidance on benefits, entitlements or individual circumstances.