CNB Research Seminar "Reach Me if You Can: How to Boost Participation of Rich Households in Wealth Surveys?"
Prague, 15 April 2026
Andrej Cupák (National Bank of Slovakia)
Andrej Cupák works as a Senior Research Economist at the National Bank of Slovakia. He also teaches and conducts research at the University of Economics in Bratislava. His main research interests are household financial decision-making and financial literacy, consumer behavior, socio-economic inequalities, well-being analysis, survey data and methodology, and applied microeconomics.
Reach Me if You Can: How to Boost Participation of Rich Households in Wealth Surveys? (abstract)
Extensive evidence shows that differential non-response in wealth surveys leads to the under-representation of rich households, biasing aggregates and distributional measures. This paper proposes and experimentally tests a targeted, incentivized oversampling strategy in the 2023/24 wave of the Slovak Household Finance and Consumption Survey (HFCS). The design distinguishes between a general population sample and a rich population sample; households in the rich sample are randomly assigned to incentivized and non-incentivized groups, with a valuable collector’s silver coin offered as a participation incentive. The incentive increases participation among wealthy households by 11–14 percentage points and raises the effective oversampling rate of the top 10%. The intervention shifts the measured wealth distribution upward, increasing the Gini index by 2.3% with oversampling alone and by 6.5% when incentives are added suggesting that standard survey-based comparative inequality measures may be strongly distorted. Employing both oversampling and incentives substantially reduces the gap between survey totals and National Accounts aggregates. Response quality does not differ significantly between treatment and control groups, while personal interviewer interaction improves data quality relative to purely online modes of contact. Our results have implications for the designers of wealth surveys.