The OSR review examined the ONS’s population estimates and projections, and found that while the estimates were “fit for purpose”, the organisation needed to do more to listen to feedback from local areas.

The review was initiated following concerns raised with the OSR in November 2020 about the ONS’s population projections and mid-year population estimates for Coventry.

The concerns were around the perceived inaccuracies of the population estimates on which the household projections and subsequent housing need are based.

Household projections data is used by national and local government, particularly in planning decisions, to determine policy.

“We found that while ONS is good at sharing its work outwardly, there is room for improvement in the way it takes on board feedback and handles challenge,” said the OSR.

“We would like to see ONS be more open and responsive to issues when they first arise and view challenge as an opportunity to improve outputs and not a criticism of its approach.

“We recognise that ONS is balancing competing priorities, but a more open and constructive approach to responding to user feedback would create opportunities for ONS to continually improve the population estimates and projections, and ensure users feel listened to.”

The review recommended improving methods, particularly in cities with large student populations, and to incorporate local insight and carry out sensitivity analysis to enhance its approach to quality assurance.

ONS should also use case studies of the use of variant projections, OSR said, be open about its short-term solution to gaps in migration data and provide specific guidance on interpreting uncertainties in population estimates and projections.

A more “open and constructive approach” should also be adopted by ONS when responding to user feedback, the OSR said.

The OSR has instructed ONS to report back on how it will address the recommendations in July 2021, with further checks against progress carried out in the second half of the year.

Ed Humpherson, director general for regulation at the OSR, said in the foreword to the report:  “The estimates are highly regarded, but there is a risk that ONS misses the bigger picture of what the population data inform and is not regularly sense checking what it does against local insight.

“We are simply urging a creative conversation that regards this sort of feedback as useful intelligence to help sense check and quality assure the ONS estimates.”