The importance of accurate GDP data is often understated and there is a need to document carefully the extent of revisions to statistics on economic activity and evaluate how this affects macroeconomic policy as well as examine ways to improve statistical methods.

The Office for National Statistics (ONS) has a trade-off between providing estimates on measures of economic activity, such as GDP, quickly, but also accurately. Information sources used to calculate GDP often take up to three years to arrive, but policymakers need to know before this the state of the economy. As such, the ONS uses a fraction (44%) of the eventual data source to make first estimates of the GDP. [...]