The effect of sugar-sweetened beverage price increases and educational messages on beverage purchasing behavior among adults

There is a paucity of evidence regarding the impact of sugar sweetened beverage (SSB) price increases on beverage consumption, using individual-level data, for the population overall and for different socioeconomic groups. This study aimed to predict the impact of altered beverage prices and educational messages on consumer purchasing behavior. 2020 adults representative of the Australian population by age, gender and income completed a discrete choice experiment online in 2016. Each subject completed 20 choice scenarios in a hypothetical convenience store setting where subjects chose between seven SSB and non-SSB beverage options or a no beverage option. Beverage prices and volumes varied between scenarios. Half of participants (n = 1012) were randomly exposed to an educational poster discouraging SSB consumption prior to completing choice scenarios. We used discrete choice models to predict purchases under several policy proposals, overall and for income and SSB consumption frequency sub-groups. Compared to baseline prices, a 10% SSB price increase was predicted to reduce SSB purchases by 15.0% [95%CI -15.2, -14.7], and increase purchases of non-SSBs by + 11.0% [95%CI 10.8, 11.2] and no beverage by + 15.5% [95%CI 15.1, 15.9]. Effects were greater with a 20% SSB price increase. Across all policy scenarios, the highest income quintile had a similar absolute and slightly greater relative decrease in SSB purchases compared to the lowest quintile. Educational poster exposure reduced SSB choice for all groups, with a greater reduction in the lower compared to higher income group, and additively increased response to price changes. Our results support the use of population-wide SSB pricing and educational interventions to reduce demand across all income groups.