Objective: To examine the relation of young people's personal income and parental social class with smoking from early to mid adolescence.
Design: Longitudinal, school based, study of a cohort of 2586 eleven year-olds followed up at ages 13 and 15.
Setting: West of Scotland.
Participants: 93% baseline participation, reducing to 79% at age 15.
Main outcome measures: Ever smoked (age 11), current and daily smoking (ages 13 and 15) and the proportion of income spent on tobacco (13 and 15) based on recommended retail prices of usual brands.
Results: Strong independent effects of parental social class and personal income were found at 11 years, both reducing with age. The higher incomes of lower class participants attenuated the social class effect on smoking at ages 11 and 13, but not at 15. Analysis within class groups showed variation in the effect of income on smoking, being strongest among higher class youths and weak or non-existent among lower class youths. This was despite the fact that the proportion of weekly income apparently spent on tobacco was greater among lower class youths.
Conclusions: The results confirm the importance of personal income and parental social class for youth smoking, but they also show that personal income matters more for those from higher class backgrounds. This suggests both that lower class youths have greater access to tobacco from family and friends and to cheaper sources of cigarettes from illegal sources. This complicates the relation between fiscal policies and smoking and might have the unintended consequence of increasing class differentials in youth smoking rather than the reverse.