The Office for National Statistics (ONS) is to change the way it calculates its much criticised official retail sales figures.
The changes, to be made following consultation with the Bank of England and the Treasury, include a number of new methods to ensure that the Retail Sales Index figures are up to date and accurate. The net impact of the changes will be a reduction in the estimates of sales volumes. There will be no impact on the estimate of sales values.
ONS has been criticised by retailers including Sir Philip Green for over-estimating retail sales levels.
Other changes include the introduction of “chain-linking”, a statistical technique which ONS claims will make sure that the Retail Sales Index improves accuracy when capturing recent trends in retail sales, including where consumers switch purchases to goods that have fallen in price.
The Retail Sales Index focus will still be on the percentage change from year-to-year, data will still include the latest monthly and 3-monthly movements.
The changes will be introduced with the Retail Sales Index figures published on May 21.