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.