“…In the first one additional datasets, usually tax registers, are utilised. Household survey data are combined with administrative records to provide more reliable income statistics at the upper tails of the distribution (Jenkins, 2017, Bartels and Metzing, 2018, Blanchet, 2018, Medeiros et al, 2018, Davern et al, 2019, Brzeziński et al, 2022. The literature on "decontamination" of low declared incomes is rather narrow.…”