Risk Analysis, Vol. 24, No. 1, 2004 Risk Comparisons, Conflict, and Risk Acceptability Claims Branden B. Johnson * Despite many claims for and against the use of risk comparisons in risk communication, few empirical studies have explored their effect. Even fewer have examined the public’s relative preferences among different kinds of risk comparisons. Two studies, published in this journal in 1990 and 2003, used seven measures of “acceptability” to examine public reaction to 14 examples of risk comparisons, as used by a hypothetical factory manager to explain risks of his ethylene oxide plant. This study examined the effect on preferences of scenarios involving low or high conflict between the factory manager and residents of the hypothetical town (as had the 2003 study), and inclusion of a claim that the comparison demonstrated the risks’ accept- ability. It also tested the Finucane et al. (2000) affect hypothesis that information emphasizing low risks—as in these risk comparisons—would raise benefits estimates without changing risk estimates. Using similar but revised scenarios, risk comparison examples (10 instead of 14), and evaluation measures, an opportunity sample of 303 New Jersey residents rated the compar- isons, and the risks and benefits of the factory. On average, all comparisons received positive ratings on all evaluation measures in all conditions. Direct and indirect measures showed that the conflict manipulation worked; overall, No-Conflict and Conflict scenarios evoked scores that were not significantly different. The attachment to each risk comparison of a risk accept- ability claim (“So our factory’s risks should be acceptable to you.”) did not worsen ratings relative to conditions lacking this claim. Readers who did or did not see this claim were equally likely to infer an attempt to persuade them to accept the risk from the comparison. As in the 2003 article, there was great individual variability in inferred rankings of the risk comparisons. However, exposure to the risk comparisons did not reduce risk estimates significantly (while raising benefit estimates), and Conflict-Claim respondents found the risk of the hypothetical factory less acceptable than No-Conflict respondents. Results suggest that neither risk com- parisons nor risk acceptability claims are automatically anathema to audiences, but they may have tiny or unintended effects on audience judgments about risky situations. KEY WORDS: Industrial risk; risk communication; risk comparisons 1. INTRODUCTION Few studies have been done on the effect of risk comparisons on public beliefs, attitudes, or be- havior; only three publications address the question of whether some types of comparisons are more effective than others. A 1988 guide for industry (1) ∗ Bureau of Risk Analysis, Division of Science, Research and Technology, New Jersey Department of Environmental Pro- tection, P.O. Box 409, Trenton, NJ 08625-0409; Branden. Johnson@dep.state.nj.us. offered recommendations based on the authors’ ex- perience and professional judgment, not empirical research. A 1990 article found no relation between the 1988 predictions and apparent preferences of cit- izens asked to rate the 14 risk comparison types out- lined in that guide. (2) A New Jersey replication of the 1990 test, (3) adding an alternative “conflict” sce- nario allegedly more typical of instances in which risk comparisons might be used, also found no rela- tion with the 1988 predictions. Putting this question of predictive accuracy aside, however, leaves enough 131 0272-4332/04/0100-0131$22.00/1 C  2004 Society for Risk Analysis