Social norms and the decline in US cigarette smoking: evidence from 30 years of US representative surveys.

Introduction: Changing social norms on cigarette smoking are proposed as a primary strategy to reduce smoking behaviour. Methods: Using core questions in 30 years of tobacco use supplements (TUS) to the Current Population Survey (CPS), we develop a state-specific, injunctive social norm scale of Willingness to Restrict Smoking (WTRS) and test its association with smoking behaviours. Respondents (n=1 462 050) to US national and state representative TUS-CPS conducted at nine regular intervals from 1992 to 2022. Results: Respondents were queried on their WTRS in 10 different settings, which varied somewhat over time. Psychometric analyses of 10 items supported a single primary dimension that accounted for 74% (SD: 7.3%) of estimated common variance. Using item response theory methods, we calibrated scores across different years and demonstrated consistency of measurement over time (differential test functioning (DTF) across adjacent years = <1% difference in scores). The resulting WTRS scale had good reliability (omega-h Conclusions: This WTRS social norm scale was likely influenced by state tobacco control programmes targeting social norms and appears to be a strong indicator of declining smoking prevalence across 30 years of US data.