We report results from a validation study of the Nielsen Homescan consumer panel data. We use data from a large grocery retailer to match transactions that were recorded by the retailer (at the store) and by the Homescan panelist (at home). The matched data allow us to identify and document discrepancies between the two data sets in reported shopping trips, products, prices, and quantities. We find that the discrepancies are largest for the price variable, and show that they are due to two effects: the first seems like standard recording errors (by Nielsen or the panelists), while the second is likely due to the way Nielsen imputes prices. We present two simple applications to illustrate the impact of recording differences, and we use one of the applications to illustrate how the validation study can be used to adjust estimates obtained from Nielsen Homescan data. The results suggest that while recording discrepancies are clearly present and potentially impact results, corrections, like the one we employ, can be adopted by users of Homescan to investigate the robustness of their results to such potential recording differences.
- Measurement error
- Self-reported data
- Validation study
ASJC Scopus subject areas
- Economics, Econometrics and Finance (miscellaneous)