Methodological Innovations in Collecting Spending Data

It has traditionally been believed that collecting survey measures of total spending necessarily involved asking a large number of questions, too many for inclusion of a comprehensive spending measure in a general-purpose survey. In this paper the authors report on a supplemental survey to the Health and Retirement Study that took up this challenge. They discuss issues that arise designing a survey module to collect spending data with strict time constraints, describe how the implementation in the Consumption and Activities Mail Survey (CAMS) played out, and elicit anomalies that more detailed analysis of data quality revealed. They report how they addressed some of these anomalies in subsequent waves of CAMS. Other anomalies required conducting additional randomized experiments to find what explains the observed patterns. The results highlight the tension between asking about spending using a long time frame, which exacerbates recall bias, versus using a short time frame, which risks relying on an unrepresentative snapshot of a household's spending to proxy the total for the last 12 months. An important complicating factor in deciding which goods should be put into which time frames is that there is substantial heterogeneity in the frequency of spending across households even for the same category of spending.