The Risks of “Putting the Numbers in Context”: A Cautionary Tale

Abstract

Despite the warnings of risk communication specialists, members of the technical community often urge that technological risks should be "put in context" by comparisons against risks that are more familiar. Little quantitative evidence is available on the actual behavioral consequences of such risk comparison efforts. In the present study, subjects were presented with two types of information about a hazardous waste incinerator--a simplified statistical summary and a comparison of incinerator risks against the risks of smoking. Statistical information led to a modest increase in the reported willingness to vote in favor of the incinerator in a community referendum, but the comparison against cigarettes led to a slight decrease in support; the difference between the two messages is statistically significant (p < .001). In combination with other results, this study's findings suggest that an implicit assumption of risk comparisons is in error: Opposition to controversial technologies may have little to do with citizens' levels of information about technology, having more to do with citizens' levels of trust in governmental and industrial actors.