[sceptic123]

> … the main household survey used to estimate consumption in the UK has a low sample size, and there appears to be a growing problem of undercoverage of expenditure … the fact that undercoverage has grown over time means that it is not clear whether the relatively modest recorded changes in consumption inequality since 1991 are genuine, or just due to an increased inability to pick up the expenditure of high-spending households.

From: https://academic.oup.com/ooec/article/3/Supplement_1/i103/74...