Willingness to Pay for Car Safety: Sensitivity to Time Framing

Stated preference (SP) surveys attempt to obtain monetary values for non-market goods that reflect individuals' “true”' preferences. Numerous empirical studies suggest that monetary values from SP studies are sensitive to survey design and so may not reflect respondents' true preferences. This study examines the effect of time framing on respondents' willingness to pay (WTP) for car safety. We explore how WTP per unit risk reduction depends on the time period over which respondents pay and face reduced risk. Using data from a Swedish contingent valuation survey, we find that WTP is sensitive to time framing; estimates based on an annual scenario are about 30 to 70 percent higher than estimates from a monthly scenario.