An investigation into procedural (in)variance in the valuation of mortality risk reductions

This study investigates whether elicited preferences are affected by the presentation of mortality risks in a stated preference survey. We elicited willingness to pay for public risk reducing initiatives under three different but outcome equivalent presentation format. Results from a discrete choice experiment demonstrate that presentation format influences the valuation of mortality risk reductions, which to varying degrees depends on the respondent's level of concern and numeracy. Marginal willingness to pay for a risk reduction increases significantly when framed in terms of avoided fatalities compared to corresponding frequencies. Furthermore, we find that less numerate respondents are more influenced by the inclusion of the number of fatalities in the presentation format. The same pattern is observed for respondents who express a higher degree of concern for a traffic accident.