On the Accuracy of Nielsen Homescan Data
By Liran Einav, Ephraim Leibtag, Aviv Nevo
Economic Research Report No. (ERR-69) 34 pp,
December 2008
Researchers use Nielsen Homescan data, which provide detailed food-purchase information
from a panel of U.S. households, to address a variety of important research topics.
However, some question the credibility of the data since the data are self-recorded
and the recording process is time-consuming. Matching purchase records from 2004
Homescan data with data obtained from a large grocery retailer, it is evident that quantities
purchased are reported more accurately in Homescan than are prices. Many of the
price differences may be driven by the way Nielsen imputes prices: when available,
Nielsen uses store-level prices instead of the actual price paid by the household. There
are also differences by household type in the tendency to make mistakes that are correlated
with demographic variables. However, the fraction of variance explained by the
documented recording errors is in line with other research data sets for which cross-validation
studies have been conducted.
Keywords: Nielsen, Homescan, scanner data, validation study, ERS, USDA
In this report ... Chapters are
in Adobe Acrobat PDF format.
- Abstract, Contents, and Summary, 275 kb.
- Introduction, 26 kb.
- Data Sources, 26 kb.
- Data Construction, 33 kb.
- Record-Matching Strategy, 155 kb.
- Do the Differences Matter?, 29 kb.
- Conclusions, 26 kb.
- References, 24 kb.
Charts and graphs (in .png format) from this report are available in the .zip file listed below. The .zip file also contains a document (readme.txt) that lists the name and title of each chart or graph file.
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Updated date: December 30, 2008
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