Populations estimates used for planning assumptions in parts of Midlands based on error, says statistics regulator

There has been an error in population estimates for parts of the Midlands on which planning assumptions have been based, the Office for Statistics Regulation (OSR) has said.

Sir David Norgrove, chair of the UK Statistics Authority, which includes the OSR, said in a letter to West Midlands MPs and local politicians that the approach taken at national level by Office for National Statistics was “fit for purpose” but at subnational level “the accuracy of estimates is variable, and OSR found that the population estimates for some cities such as Coventry did seem to be inconsistent with local evidence”.

Sir David said this also appeared to be the case in some other smaller cities with large student populations.

The ONS will investigate the causes and scale of this issue and “be more ready to respond to challenge”.

Sir Andrew Watson, chair of the Campaign to Protect Rural England’s Warwickshire branch, had complained to the OSR that population figures and projections issued by the ONS for Coventry were wrong.

He said: “Because ONS population projections and associated household projections are used as the basis for forward planning by all local planning authorities, the very high figures for Coventry have led that authority and neighbouring Warwickshire authorities to over-allocate land for housing in their local plans.

“This has resulted in major incursions into the countryside, both in Coventry itself and in those parts of Warwickshire immediately surrounding it.”

Sir Andrew said the 2011 census showed Coventry with a population of 317,000, yet the ONS estimated that had risen to 371,500 by 2019, which he said arose from the ONS having overestimated Coventry’s birth rate and underestimated the death rate.

A similar issue has occurred in Guildford where Dawn Hudd, strategic services director of Guildford Borough Council, said the population estimates were too high.

OSR director Ed Humpherson replied: “We conducted our own research and spoke to a number of expert demographers, academics and representatives from local government.

“We found that the population estimates for some cities, such as Guildford, did seem to be inconsistent with, and potentially higher than local evidence would suggest.

“This also appeared to be the case in a number of smaller cities with large student populations.”

Mark Smulian