Measuring top wealth shares in the UK

We examine how the measurement of aggregate wealth affects our understanding of wealth distribution. We explain why choices over wealth aggregates can affect the measured level and composition of wealth concentration. Applying this to the UK, we find estimates of the top 1% wealth share vary by 2.1pp – between 14.4% and 16.5% – in 2016–18, depending on the choices we make regarding aggregates and the source of distributional information. Alternative definitions for aggregates lead to a reranking of who is at the top, replacing 40% of individuals in the top 1%, and changing the share of women and older individuals. We discuss conceptual and measurement issues with the National Accounts as a source of wealth aggregates, and argue that in many cases they are poorly aligned in both regards with the measure of personal wealth one would like to target, and in practice are less comparable internationally than they initially seem. In the UK, where the wealth survey has reasonably good coverage across the distribution, we therefore prefer survey aggregates.