FOI reference: FOI-2024-1813

You asked

On 1 December 2023 ONS published its most recent analysis on transformation of UK consumer price statistics. Amongst other things, this release confirmed that the official source for used car price inflation data will be moving to Autotrader from March 2024.

ONS also published an analysis of how the previous 7 years of consumer price statistics would have appeared had this source (along with other improved methods and data sources) been used. This analysis was set out in an excel file which also set out the specific 'transport' component of these statistics. Please provide the 7 year back-cast of the CPI and RPI used car price index setting out how these would have appeared had Autotrader been used as the official data source (which would have been produced in order to produce the broader analysis of the 'transport' component).

We said

Thank you for your request.  

The seven year back-cast of the CPI and RPI used car price index is due to be published by ONS on Wednesday 20 March 2024 at 7:00am as part of an update to the impact analysis on transformation of UK consumer price statistics: private rents and second-hand cars, UK, dataset (Impact analysis on transformation of UK consumer price statistics: private rents and second-hand cars, UK - Office for National Statistics).

As such, Section 22(1) of the Freedom of Information Act 2000 applies, whereby information is exempt from release if there is a view to publish the information in the future. As a central government department and producer of official statistics, we need to have the freedom to be able to determine our own publication timetables. This is to allow us to deal with the necessary preparation, administration and context of publications. It would be unreasonable to consider disclosure when to do so would undermine our functions.

This exemption is subject to a public interest test. We recognise the desirability of information being freely available and this is considered by ONS when publication schedules are set in accordance with the Code of Practice for Statistics. The need for timely data must be balanced against the practicalities of applying statistical skill and judgement to produce the high quality, assured data needed to inform decision-making. If this balance is incorrectly applied, then we run the risk of decisions being based on inaccurate data which is arguably not in the public interest.  This will have an impact on public trust in official statistics in a time when accuracy of official statistics is more important to the public than ever before.