US state cigarette tax increases and smoke-free legislation in relation to cigarette expenditure across household socio-economic circumstances: a quasi-experimental study.

Every $1.00 cigarette tax increase was associated with a 1.5 percentage point (-0.028, -0.002) reduction in any cigarette expenditure and an increase of 0.1% (0.1%, 0.1%) budget share and $10.11 ($8.38, $11.84) absolute expenditure. The association with absolute expenditure was stronger among smoking households above poverty level ($10.73; $8.94, $12.51) than below ($4.72; $2.37, $7.07). The enactment of smoke-free legislation was associated with $2.33 (-$4.56, -$0.10) less expenditure, but not with any expenditure (0.1%; -1.6%, 1.8%) or budget share (-0.1%; -0.1%, 0.1%). The association with absolute expenditure was stronger among households above poverty level (-$2.62; -$4.95, -$0.29) than below (-$0.34; -$4.27, $3.58) CONCLUSION: Cigarette tax increases in the United States between 2000 and 2014 may have reduced smoking prevalence due to an absolute and relative increase in household tobacco expenditure while smoke-free policies appear to have led to a reduction in expenditure. Although tax increases had a stronger impact on absolute expenditure among households above the poverty level, impact on relative expenditure was similar, and consequences for socio-economic inequalities in smoking will vary based on the broader financial situation of households.