Does an oath improve demand revelation in discrete choice experiments?

This project considered the potential of ex ante corrections to improve demand revelation and reduce hypothetical bias in discrete choice experiments. Theories of social psychology emphasise that social context is important when individuals are asked to value non-market goods. We used an induced value experiment to investigate demand revelation and hypothetical bias in discrete choice experiment responses. This project drew on existing research of Drs Luchini and Jacquemet and Professor Shogren by asking participants to complete one of three oaths before taking part in the experiment. Commitment theory suggests that this should increase demand revelation and reduce hypothetical bias.

Outcome and Translation

We find that an oath improves the reliability of responses to hypothetical DCE-type tasks. We find oaths that target honesty are more effective than those that target effort.

HERU researchers involved in this research project: Verity Watson

External collaborators: N Jacquemet (University of Paris); S Luchini (GREQAM, Marseille) and J Shogren (University of Wyoming)


Jacquemet, N., Luchini, S., Shogren, J. and Watson, V. (2014) 'A discrete choice experiment under oath.', Health Economics in the Age of Longevity: a Joint iHEA & ECHE Congress, Trinity College, Dublin, 13-16 July 2014.

Watson, V. (2014) 'Discrete choice experiment under oath', Stirling Choice Workshop, University of Stirling, 14 October 2014.

Watson, V. (2017) 'Using social psychology to improve stated preference responses: evidence from the lab', Behavioural Science Centre Workshop on Valuation and Well-Being Stirling University, Stirling, 10 March 2017.