UK 'flying blind' in key policy areas thanks to unreliable official data

The UK is increasingly "flying blind" in key policy areas as the quality of official statistics declines, experts have warned.

- Becky Pinnington

In November, the Office for National Statistics (ONS) admitted that it had overreported net migration by a fifth in 2024 – the provisional figure of 431,000 was revised down to 345,000 – renewing concerns about the reliability of its data. The ONS also said it undercounted both immigration and emigration, with estimated emigration of British nationals revised up from 77,000 to 257,000 last year.

The ONS has faced data quality problems with several of its leading studies in recent years. Since the beginning of 2024, a total of 30 releases have lost their "accredited official statistics" designation - the highest quality mark the UK Statistics Authority can bestow.

To put that into context, there were 30 de-designations in the entire period from October 2015 to the end of 2023.