Incentivized and non-incentivized liking ratings outperform willingness-to-pay in predicting choice

A core principle in decision science is that people choose according to their subjective values. These values are often measured using unincentivized scales with arbitrary units (e.g., from 0 to 10) or using incentivized willingness-to-pay (WTP) with dollars and cents. What is unclear is whether using WTP actually improves choice predictions. In two experiments, we compare the effects of three different subjective valuation procedures: an unincentivized rating scale, the same scale with incentives, and incentivized WTP. We use these subjective values to predict behavior in a subsequent binary food-choice task. The unincentivized rating task performed better than the incentivized WTP task and no worse than the incentivized rating task. These findings challenge the view that subjective valuation tasks need to be incentivized. At least for low-stakes decisions, commonly used measures such as WTP may reduce predictive power.