Is 1 out of 20 riskier than 5%? effect of representing unlikely events as ratio versus percentage on risk perceptions

Purpose The purpose of this paper is to investigate whether the numeric representation of a relatively low risk in terms of a ratio versus a percentage affects risk perception. Design/methodology/approach We propose a conceptual framework that explains the differential effects of ratio and percentage formats on risk perceptions and purchase intentions. We investigate the process driving the differential effects, and delineate boundary conditions. We experimentally show that a ratio representation is more concrete than a percentage, engendering more pronounced mental imagery, higher negative affect and risk perceptions and lower purchase intentions. Findings The extent to which individuals can imagine themselves in the risk situation is higher when the risk is described as a ratio compared to an equivalent percentage, inducing greater negative affect, and higher risk perceptions. Further, individuals’ construal level moderates the effect of frequency format on risk perceptions. Finally, they show that impairing individuals’ spontaneous process of imagining the risk by encouraging a more “rational” processing of the risk information attenuates the effects of frequency format. Research limitations/implications They examine how the numeric representation of relatively low risks in terms of a ratio versus a percentage affects risk perceptions. Practical implications They outline strategies that could be used to affect risk perceptions, and product purchase decisions and related behaviors. Social implications Communicating risk in a manner to encourage individuals to take preventive measures is better achieved with frequency information presented as a ratio versus a percentage. Originality/value They propose a comprehensive framework that explains the differential effect of frequency format on risk perceptions. They experimentally demonstrate that a ratio representation is more concrete than a percentage, engendering more pronounced mental imagery, higher negative affect and risk perceptions.