Economic valuation of road injuries in Japan by standard gamble

Abstract

During fiscal year 1997 the Ministry of Land, Infrastructure, and Transport of Japan introduced a system for evaluating road investment projects that considers reduction of road accidents as well as savings in time and running costs. However, the unit cost to calculate the benefit of reducing road accidents was not based on willingness to pay. In this study, we estimated the weight of road injuries against fatalities based on Japanese people’s preferences by a standard gamble approach. In the primary investigation, we estimated the weight of serious injuries based on social preference as well as usual private preference; no obvious differences were observed. Our results were slightly larger than those in the United Kingdom. In the secondary investigation, we estimated the weight of slight injuries and serious injuries using standard gambles. We prepared two questionnaires to assess whether differences in choices affect the results. There was no conclusive proof either way. Finally, we expressed the loss of road injuries in monetary terms by multiplying the weight of injuries to the value of a statistical life and derived a much higher estimate of total costs due to accidents than did the Japanese government.