Parental Income and Children’s Smoking Behaviour: Evidence from the British Household Panel Survey

1. Parental Income and Children’s Smoking Behaviour: Evidence from the British Household Panel Survey Andrew Leicester Laura Blow Frank Windmeijer

2. Child Smoking – targets • Government target: Reduce proportion of children aged 11 – 15 who smoke regularly from 13% (1996) to 11% by 2005 and 9% by 2010 • “Smoking Kills – A White Paper on Tobacco” (1998)

3. Child Smoking - progress 2005 target 2010 target Source: Smoking, Drinking and Drug Use among Young People in England in 2004" (Department of Health)

4. Current evidence • Tyas and Pederson (1998) • Literature review of determinants of youth smoking • Consider parental socioeconomic status and children’s personal income: • “Higher levels of parental socioeconomic variables, such as education and social class, have often been found to be inversely related to smoking status in adolescents …” • “… young people with more spending money showed higher levels of smoking …”

5. Further studies • Soteriades and DiFranza (2003) • Study of Massachusetts teenagers • Controlling for children’s demographics and parental smoking, find: • “The risk of adolescent smoking increased by 28% with each step down in parental education, and by 30% for each step down in parental household income” • Conrad et al (1992) • Around ¼ of studies did not support an inverse relationship between parental SES and childrens’ smoking

6. Measuring effect of income • How might parental income affect children’s smoking behaviour? • Higher incomes allow parents to “buy” circumstances conducive to lower smoking rates • School, peer, neighbourhood effects? • But also allow greater consumption of all goods, including cigarettes • Clear that relationship between parental income and youth smoking may be indirect • Concern that we may not be able to fully observe these indirect channels

7. Innovations of our approach • Exploit relatively under-used data from the British Youth Panel (BYP) and British Household Panel Survey (BHPS) • A more direct assessment of the extent to which parental incomes are associated with youth smoking • Use sibling differences to assess possible causal effect of income on smoking • Strips out unobservable household effects that determine smoking and are correlated with income

8. Data • British Household Panel Survey (BHPS) / British Youth Panel (BYP) • 1994 to 2001 (waves 4 to 11) • BYP separate data for children aged 11 – 15 in BHPS • Data from BYP on children’s smoking and characteristics • Data from BHPS on family backgrounds, SES, income, smoking status of adults • Track children from BYP into BHPS up to age 18

9. Sample Sizes • Sibling sample cases where we observe two or more siblings reaching the same age at different points in time • Used in sibling difference analysis later

10. Smoking behaviour in the BYP • Child a smoker if: • Responds with positive figure to question “how many cigarettes did you smoke in the last seven days?” or • Self-defines as someone who smokes but not every week • BHPS question is direct yes/no

11. BYP evidence on youth smoking: over time

12. BYP evidence on youth smoking: by household income decile

13. Household income and youth smoking: models • Simple probit for whether child smokes • Models all condition on: year, age, gender, region, household composition, mother’s age • In addition: • Condition on household income quintile and then other family background characteristics

14. Results *** = significant at 1% level; ** = significant at 5% level

15. Results *** = significant at 1% level; ** = significant at 5% level

16. Results *** = significant at 1% level; ** = significant at 5% level

17. Sibling Differences • Income correlated with observable features of the data, e.g. maternal education • May also be correlated with unobservable features of the data – peer effects, neighbourhood effects, household preferences, etc. • Therefore examine relationship between changes in income over time and changes in sibling smoking behaviour

18. Sibling Differences • Focus on siblings who reach same age at different points in time • 1,030 pairs of siblings identified Older Sibling Younger Sibling

19. Model • Define ∆S = 0 if both siblings smoke/don’t = 1 if only younger smokes = -1 if only older smokes ∆S = f(∆Y, year, age, sex, ∆sex, mother age, age gap between siblings) NB ∆Y positive if household income rose by the time younger sibling reached same age as older

20. Results

21. Results

22. Results

23. Conclusions • Inverse relationship between household income and youth smoking • Effect fades once we control for maternal education and presence of adult smoker • Sibling difference results suggest no direct causal relationship between household income and youth smoking • If anything, higher incomes increase the likelihood of children smoking slightly