The somewhat ad-hoc method of certainty calibration, based on self-stated preference certainty follow-up questions, has been found to be a successful method of eliminating or reducing hypothetical bias in stated preference studies. But is the preference certainty really context dependent, or do...

This study is the first to analyze hypothetical bias in a willingness to pay for time context as well as the first to test certainty calibration of the value of time. Hypothetical and real actions are compared in an experimental setting where the subjects are given an offer to leave the...