Choice certainty, consistency, and monotonicity in discrete choice experiments

This study investigates choice certainty, choice consistency, and choice monotonicity and their underlying common and idiosyncratic determinants in discrete choice experiments. We test the equality of choice behaviour between respondents who differ with respect to these concepts. Our results suggest that there are significant differences in the choice behaviour between certain and uncertain, as well as consistent and inconsistent, respondents. The hypothesis of equality of choice behaviour between samples with and without a self-reported choice certainty follow-up question cannot be rejected. We identify a variety of idiosyncratic determinants of choice certainty, consistency, and monotonicity, but only the time spent reading informational pages and gender are identified as common drivers. We find that female respondents are less certain about their choices, but display a higher degree of monotonicity and consistency in their choice behaviour.