Modeling Behavioral Economics Strategies in Social Marketing Messages to Promote Vegetable Consumption to Low-Resource Louisiana Residents: A Conjoint Analysis.

ABSTRACT

BACKGROUND: Behavioral economics strategies implemented within social marketing campaigns improve eating behavior. OBJECTIVE: To identify which behavioral economics strategies in social marketing messages particularly messengers, norms, and commitments will promote low-income Louisiana residents to add more vegetables to meals. DESIGN: Full profile traditional conjoint analysis survey with single concept ratings. PARTICIPANTS: Purposive sample of low-resource Louisiana residents (N = 213) SETTING: Online survey. INTERVENTION Participants rated randomized concepts that featured a messenger and a message. MAIN OUTCOME MEASURE: Ratings (one to nine) of likelihood to add vegetables to meals. STATISTICAL ANALYSIS: A model of ratings was generated using mixed-effects multiple regression, which accounted for repeated measurement of participants. Interactions of variables and covariates were modeled. RESULTS: There was a significant main effect of the messenger variable (P = 0.02) and main effect of the message variable (P = 0.008). Pairwise comparisons demonstrated differences between friend (µ (predicted mean) = 6.80) and mother (µ = 7.06; P = 0.03) as well as friend and normal-weight doctor (µ = 7.03; P = 0.04). Pairwise comparisons demonstrated differences between descriptive norm (µ = 6.79) and grocery list precommitment (µ = 7.02; P = 0.05) along with descriptive norm and injunctive norm (µ = 6.98; P = 0.04). Covariate models demonstrated main effects of race (P = 0.006) and sex (P = 0.0001). There was significant variation in the message variable and frequency of vegetable intake interaction (P = 0.01). CONCLUSIONS: Both message and messenger variables predicted the likelihood to add vegetables to meals. Race and sex influenced ratings to add vegetables. As reported vegetable consumption increased, behavioral economics messages improved the likelihood to add vegetables to meals. Behavioral economic approaches are well suited to social marketing messages that aim to promote healthy eating behavior in low-income LA residents.