Information "black holes" are leaving some of the most vulnerable groups in society "invisible" to policymakers, the UK's equalities watchdog has warned.
The Equalities and Human Rights Commission (EHRC) on Friday published a wide-ranging review of Britain's progress on equality and the protection of human rights since 2010, drawing on data sets provided by public bodies, regulators, inspectors and NGOs.
While the watchdog found that overall income inequality had fallen since 2010, it highlighted a "deepening inter-generational divide" since the financial crisis, with people under 34 experiencing the sharpest fall in incomes, employment, access to housing, and pay. The report also warned that poor white boys are suffering from "a combination of disadvantage", experiencing higher rates of school exclusion and the lowest academic results of all children.
Departments need to deal with their data gaps if government is serious about tackling inequality
Civil service diversity: perm secs get "data driven and measurable" objectives for boosting Whitehall representation
The benefits and challenges of harnessing data
But while the report's authors were able to provide detailed insights into the lives of some groups, they found that other marginalised groups – including transgender people, those aged over 80, and gypsies and travellers – were slipping under the radar of public authorities because of a lack of information.
Laura Carstensen, commissioner at the EHRC, said gaps in the data available to public bodies could limit understanding of the problems facing "some of Britain’s most vulnerable groups".
"Targeted research would help us to identify the nature and scale of such issues and to consider how best to help," she added.
"Ignoring problems because of data gaps may result in worse problems in the long run. Good quality, accessible and timely data is also vital in ensuring that finite resources are targeted in the most efficient and effective way."
The commission said there was now a "sparseness of data" on school bullying following a 2010 decision to axe the anonymous TellUs survey run by the then-Department for Children, Schools and Families, meaning the EHRC has had to rely on "intermittent surveys" by charities and NGOs.
And they said that the 2010 cancellation of the Citizenship Survey – which saw officials from the Department for Communities and Local Government regularly quiz more than 10,000 adults on issues including experiences of racism and attitudes to violent extremism – had "significantly limited" the amount of evidence available on discrimination.
Writing for Civil Service World, the EHRC's Verena Brähler said that while data availability had improved on some fronts – with more information now collected on the outcomes of vulnerable children – in some cases policymakers now had "less detailed information compared to five years ago" because authorities had simply "stopped running certain surveys" .
"The reductions of sample sizes in major national surveys have also limited our ability to obtain statistically robust findings for all protected characteristics," she said.
"For example, the sample size of the Family Resources Survey was reduced by 5,000 households across Great Britain in April 2011. The sample size of the Crime Survey for England and Wales was reduced from 46,000 adults in 2008/09 to 35,000 in 2012/13."
Brähler added: "Another issue is that people are combined into one big group, even though their experiences differ. This is the case, for instance, with disabled people who are often lumped together in one category, regardless of the nature of their impairment."