Reducing the gap between stated and real behavior in transportation studies: The use of an oath script

Abstract

We investigate whether taking an oath in a survey situation affects respondent behavior in choice experiments with a focus on travel time, comfort, and cost. We conduct two studies in Beijing: one with car commuters and one with public transport commuters. Overall, we find little difference in behavior between responses with and without an oath. In fact, the only difference is that responses are more internally consistent in the version with an oath script: the respondents trade off money in terms of a fuel cost and in terms of a congestion charge in the same way. However, there is no statistically significant effect on marginal willingness to pay for any of the attributes.