Score contribution per author:
α: calibrated so average coauthorship-adjusted count equals average raw count
In response to the health impacts of smoking, cigarette packs with health warnings have proven effective. However, it remains undetermined whether enhancements or modifications could amplify their impact, in helping smokers to quit and/or deterring initiation. We aimed at providing new evidence on this issue by using different motivational leverages identified in the psychology and economic literature. We developed new warnings based on commitment, cognitive dissonance, empowerment and Electronic Nicotine Delivery Systems use. To determine which types of warnings are the most effective, we conducted an online experiment where participants (n = 860, including 335 smokers) were exposed to a specific type of warning, using conventional regulatory warnings as a control. Traditional indicators (measures of emotions, reactions, beliefs, perceived efficacy and intentions) and an innovative behavioural indicator (incentive-compatible willingness-to-pay) were used to assess the efficacy of the warnings. The conventional regulatory warnings performed at least as well as the alternative ones in almost all the relevant dimensions. In this respect, alternative warnings are disappointing, although some have a positive effect compared to no warning and may be used as a basis for complementary or targeted warnings or prevention measures in other contexts.