Using a Randomized Voucher Experiment to Determine Demand for Carbon Monoxide Alarms in a Social Marketing Program

Background: We report on a social marketing campaign conducted in Baltimore homes to promote carbon monoxide (CO) alarms including the use of community outreach, vouchers, and a mobile van to increase availability. This article focuses on the impact of the vouchers and measures the price sensitivity of individuals in their willingness to obtain a CO alarm. Methods: The study provided all 712 participants a health education message about the importance of CO alarms. Then each received one of five randomly selected vouchers that would make the price of a CO alarm US$0, US$5.50, US$11.00, US$16.50, or US$22.00 and that could be redeemed at mobile van that was parked in their neighborhood. Results: The study found that the more the CO alarm was discounted, the more likely the voucher was to be redeemed. Discounting the price to US$0 had a larger effect than any other price point. Individuals who already owned CO alarms were more influenced by the free price point than individuals who did not have CO alarms at baseline, and some of these individuals appear to have installed more than one CO alarm in their dwelling. Homes with children were less likely and homes with older adults were more likely to redeem the vouchers. Conclusion: Making CO alarms free has the largest impact on the total number of CO alarms distributed. Individuals who already had CO alarms are more attracted to free CO alarms than individuals with no CO alarm.