cover, as well as their geographic reach, methods for collecting information, and data completeness. Additionally, a number of potential problems can limit the utility of the data regardless of the vendor, including but not limited to:
An unexpected sudden change in methodology or wholesale cessation of data collection by the vendor could leave a critical gap in the CE estimation process.
Aggregate retail data are likely of best use for the CE, therefore, if information about specific products or channels is purchased from third-party vendors, not collected and aggregated directly by BLS. A thorough vetting process for such data before use is important so that the limitations of the data are well understood.
Use of alternative microdata. The previous section addressed administrative data sources from retailers. But microlevel data at the respondent level could play a role in reducing cost and/or increasing accuracy in the CES. New types of electronic data—financial records, budgeting software, store loyalty card information—may also be captured and utilized at the household or respondent level. Such data likely have the greatest utility in enhancing recall during the CE survey, but may also in some instances serve to replace survey elements, thereby reducing respondent burden, recall (measurement) error, and data collection costs.
These data may be used in one of two ways by the CE: (1) as memory cues, i.e., tools to aid respondents in their reporting of purchases that they may have otherwise forgotten and/or misreported; or (2) as data to be extracted and used in place of self-reported information.
As memory-jogging devices, microdata records could be printed or reviewed on a computer screen at the time the interview is conducted. Respondents would be encouraged to review their records to remind themselves of specifics of a purchase (date, place, item, and price). Utilizing records in this fashion would increase the time burden faced by respondents, but it could have a positive effect on data quality by reducing reporting error.