Sign-dependent Value of Time in Stated Preference: Judgment Bias or Exposure of Genuine Preference?
Stated choice surveys may be the most common approach to obtain monetary values of travel time. The large surveys of 1988 and 1997 in the Netherlands and of 1994 in the United Kingdom produced some puzzling outcomes, such as differences in monetary valuation between travel time gains and losses. This has given rise to controversies about the behaviour that might have caused this ‘sign effect’, which are not decisively settled. This paper shows that Prospect Theory and the heuristic judgment concept as developed in behavioural sciences can shed more light on these controversies2. It starts with an introduction of some basic principles of these lines of work before re-examining the Dutch and UK surveys from these points of view. It is concluded that the sign effect is not caused by biases that stem from heuristic judgment but follows from lossaversive valuation of time and money attributes as assumed in Prospect Theory.
EJTIR is licensed under a Creative Commons Attribution 4.0 International (CC BY 4.0) licence. The license means that anyone is free to share (to copy, distribute, and transmit the work), to remix (to adapt the work) under the following conditions:
- The original authors must be given credit
- For any reuse or distribution, it must be made clear to others what the license terms of this work are
- Any of these conditions can be waived if the copyright holders give permission
- Nothing in this license impairs or restricts the author's moral rights