Statistical analyses
REGRESSIONS
Descriptive statistics were reported for the independent variables. For the outcome variables, the means (or percentage) and 95% confidence intervals were reported across the five conditions to detect any statistically significant differences among conditions in the answers of the respondents. To confirm that randomization across the five conditions was properly performed, Ordinary least squares regressions were used to estimate Comparisons across experimental conditions were made by assigning the reference category to the control group (condition 1, 2, 3, or 4) and estimating the relative effect of the treatment group (condition 2, 3, 4, or 5) on the outcome variables. In particular, the effects of:combined health warnings relative to text-only warnings (on packages with brand logos) (condition 2 relative to 1),new warnings relative to old warnings (on packages with brand logos) (condition 3 relative to 2),PP relative to branded packages (when old warnings were displayed) (condition 4 relative to 2),PP relative to branded packages (when old warnings were displayed) (condition 5 relative to 3),new warnings relative to old warnings (on plain packages) (condition 5 relative to 4) were estimated.