Dear Lord Bailey,

Thank you for your letter to the National Statistician regarding the Mayor of London’s use of housing statistics in a LabourList article from March 2024. This was passed to the Office for Statistics Regulation (OSR), the regulatory arm of the UK Statistics Authority.

The Mayor’s comments appear to draw from the Greater London Authority’s (GLA) Affordable Housing starts and completions statistics. The statistics are broken down into house building ‘starts’ and ‘completions’. These definitions are clear and describe a real-world picture of what the statistics represent: whether a dwelling has started construction or whether construction has finished.

There were 25,658 affordable housing starts in the period April 2022 to March 2023, and 13,954 affordable housing completions during this time. The Mayor’s use of the word ‘delivered’ could be misinterpreted by the average person to mean the housing had been completed rather than started. While the Mayor would not have had access to the statistics for the equivalent period in 2023/24 at the time of writing the article, the number of affordable housing starts and completions for 2023/24 was 2,358 and 10,949 respectively. The reference to ‘within the last year’ may have been intended to reflect the latest year of statistics that were available, but this would not be clear from the statement alone.

In line with the principles of intelligent transparency, when making numerical claims, public figures should be clear what they are referring to and consider how a reasonable person would interpret the claim. To help the public understand statistical claims made during the General Election debates, the OSR has recently published a series of explainer articles including on housing supply and affordability statistics.

Yours sincerely,
Sir Robert Chote


Related links

Lord Bailey of Paddington AM to Sir Ian Diamond – housing statistics