Concerns regarding ONS GDP statistics during the pandemic
Thank you for your email about ONS statistics on public service outputs during the pandemic. It has been, and remains, a very tricky job for ONS to measure public service outputs during the pandemic. It is a challenge to communicate the countervailing forces on public output with some Covid-19 responses increasing output, such as increases to critical care, and some depressing it, such as delayed operations and school closures. More broadly, though, the UK’s National Statistics on GDP during the pandemic are compiled on a comparable basis to pre-pandemic GDP figures, so high-level comparison of UK GDP over time is reasonable.
You are right that the UK’s figures on GDP changes are not completely comparable with those of many other countries. As your blog indicates, this is less because the UK’s approach is flawed conceptually or practically, and more because not all countries measure public services output in the conceptually sound way that the UK does.
This means that you are right that people should be cautious about comparing changes in GDP in the UK with other countries, unless they are clear that the methods are comparable or that the differences in public service output are not significant. ONS issues warnings to users to be cautious and wary of making such comparisons, but they could perhaps be more prominent. The degree of international comparability is also an issue that international bodies like OECD could explore further.
Your blog, and the questions it raises, is a very timely reminder of the ongoing need to identify and explain to users the relevant limitations arising from the methods used to produce statistics. ONS is planning an article that should shed light on the extent of difference between the UK and other countries.
ONS took a very positive step in its 22 December GDP figures when its headline estimates of health care output included an explicit adjustment for the track and trace system. This will also prepare the groundwork to capture the mass vaccination programme that began in early December. ONS has also strengthened its relationship with the NHS enabling it to increase the ‘data content’ of its first estimates of GDP: basing these early estimates on the most-timely data on healthcare activity possible.
Director General for Regulation