This study examined the effects of (a) the processes of risk reduction to achieve zero risk and (b) the framings of the problem on the value of achieving zero risk. Respondents assessed WTPs (willingness to pay) to save lives in a hypothetical earthquake. two factors were manipulated in the experiment. These were (1) the process to present risk reduction as an increase in lives saved or a decrease in deaths. The results suggested that the zero risk effect, which meant the identical loss reduction by a protective action against risk was valued more highly when it achieved the "no loss" outcome than when it left some losses, disappeared in the condition where zero risk was achieved by one-to-one actions with corresponding one-to-one costs. rather, people valued the first protective action more highly than the following actions in that condition, particularly when the problem was framed positively. Zero risk effect appeared only in the condition where a single-shot action could achieve zero risk.
