Eliciting Risk Perceptions: Does Conditional Question Wording Have a Downside?

Background: For assessing the impact of risk perceptions on prevention efforts or behavior change, best practices involve conditional risk measures, which ask people to estimate their risk contingent on a course of action (e.g., “if not vaccinated”). Purpose: To determine whether the use of conditional wording—and its drawing of attention to one specific contingency—has an important downside that could lead researchers to overestimate the true relationship between perceptions of risk and intended prevention behavior. Methods: In an online experiment, U.S. participants from Amazon’s MTurk (N=750) were presented with information about an unfamiliar fungal disease and then randomly assigned among three conditions. In all conditions, participants were asked to estimate their risk for the disease (i.e., subjective likelihood) and to decide whether they would get vaccinated. In two conditional-wording conditions (one of which involved a delayed decision), participants were asked about their risk if they did not get vaccinated. For an unconditional/benchmark condition, this conditional was not explicitly stated but was still formally applicable because participants had not yet been informed that a vaccine was even available for this disease. Results: When people gave risk estimates to a conditionally-worded risk question after making a decision, the observed relationship between perceived risk and prevention decisions was inflated (relative to in the unconditional/benchmark condition). Conclusions: The use of conditionals in risk questions can lead to overestimates of the impact of perceived risk on prevention decisions, but not necessarily to a degree that should call for their omission.