A Computer-Based Incentivized Food Basket Choice Tool: Presentation and Evaluation

We present and evaluate a new incentive-based tool to measure people’s dietary
choices in a low-cost and time effective manner. Respondents are asked to allocate
a fixed monetary budget across a choice of around a hundred grocery items with the
prospect of receiving these items with some probability delivered to their home by a
real supermarket. The tool has the advantage of offering a broad coverage of dietary
choices, allows inference of macro-nutrients and calorie, and allows the researcher to fix
the choice set participants can choose from. We compare the information derived from
our incentivized tool, and compare it to alternative low-cost ways of measuring dietary
intake, namely the food frequency questionnaire and a one-shot version of the 24
hour dietary recall, which are both based on self-reports. We invited 255 low income
participants to our laboratory and collected measures using these three alternative
tools. We compare the calorie intake indicators derived from each tool with a number
of biometric measures for each subject, namely weight, body-mass-index (BMI) and
waist size. The results show that the dietary information collected is only weakly
correlated across the three tools. We also find that only the calorie intake measure from
our incentivized tool is positively and significantly related to each of these biometric
indicators. By contrast, we find no significant correlations for either of the two measures
based on self-reports. We therefore argue that our tool may be useful for research
conducted with limited time and budget.