Inoculation in competitive framing examining message effects on policy preferences

Recent years have witnessed increased scholarly attention to the competitive and dynamic nature of message framing in shaping public opinion. The current study extends our understanding of competitive framing in the context of public opinion about taxes on sugar-sweetened beverages (SSBs) using insights from communication research on inoculation theory. We report on a two-wave longitudinal framing experiment (N = 3,118), testing effects of eight different experimental conditions, to examine the impact of exposure to several combinations of pro-tax frames, anti-tax frames, and inoculation as a counterframing strategy, relative to a no-exposure control group. Respondents exposed to an inoculation message that illuminated source motives and preemptively refuted soda company arguments elicited more favorable opinions of SSB taxes immediately after exposure compared with those not exposed to any message. Immediate effects of the inoculation message on policy opinions occurred via two complementary psychological mechanisms: a persuasion effect via changes in beliefs about soda companies (the source of the attitudinal threat described in the inoculation message) and an applicability effect via changes in the salience of beliefs about soda companies in shaping tax support. Inoculation did not, however, produce sustained resistance to subsequent strong anti-tax frame exposure in an asymmetric competitive framing context. We conclude by discussing the implications of this research for future work on competitive framing in a US policy context.