Behavioural economic studies of tobacco control : excise tax, alternative products, and application to priority populations in New Zealand.
Degree GrantorUniversity of Canterbury
Degree NameDoctor of Philosophy
Objectives Tobacco control is a multidisciplinary field which uses theory and research from medicine, public health, economics and psychology in an attempt to reduce the harm associated with tobacco cigarette smoking, a leading cause of preventable death in most developed countries. This thesis uses a psychological approach to study potential tobacco control policies relevant to New Zealand, primarily based on the psychology of addiction and the behavioural economic analysis of price policy and alternative products. Specifically this research is the first to use simulated demand procedures to compare price sensitivity for Maori/Pacific and New Zealand European smokers, and to compare ratings and substitutability of e-cigarettes between these ethnic groups. In addition, the first evaluations of simulated demand and subjective effects for Very Low Nicotine Content cigarettes and for varying nicotine levels in electronic cigarettes are reported. Finally, simulated demand and short-term uptake of electronic cigarettes are modelled using a combination of two subjective effects measures, representing the first attempts to model how initial experience of electronic cigarettes affects intended and actual use of these products.
Methods Five empirical studies use behavioural economic simulated demand procedures and psychological measures of dependence, smoking behaviour and subjective effects to examine the potential impact of price policy and alternative products on demand and smoking-related behaviour. The first two studies use data from the Cost of Smoking Study [N=357], a survey of smokers from four New Zealand cities who responded in 2012, 2013 and 2014, before and after two annual 10% tobacco excise tax increases. Group comparisons were performed to compare Maori/Pacific and New Zealand European smokers. Two original laboratory studies assessed subjective effects, simulated demand, and substitutability of alternative products after a brief ad libitum sampling period. Very Low Nicotine Content cigarettes were compared with regular cigarettes [N=40], and electronic cigarettes of varying nicotine contents were compared [N=46]. The Modified Cigarette Evaluation Questionnaire was used to evaluate subjective effects associated with smoking, and hypothetical purchase tasks were used to generate simulated demand data. Finally, a follow-up field trial examined subjective effects, smoking behaviour and electronic cigarette use over a two week period when ecigarettes of varying nicotine contents were available [N=35]. Mixed model analyses were used to assess use of both products, and to model e-cigarette use using subjective effects data.
Results The exponentiated demand model provided good fits for simulated demand data for regular cigarettes, Very Low Nicotine Content cigarettes and electronic cigarettes, for Maori/Pacific and New Zealand European smokers. Maori/Pacific smokers, especially males, appeared to be more price sensitive based on reported actual behavioural change after two excise tax increases, and simulated demand data. Very Low Nicotine Content cigarettes were partially substitutable [CPE=.32] but had reduced reinforcing effects relative to regular cigarettes. Electronic cigarettes were partially substitutable for regular cigarettes regardless of nicotine content [CPE=.20-.25] but subjective effects and demand varied by nicotine content for first-time users; withdrawal symptom alleviation increased as nicotine increased but taste and enjoyment factors decreased. Smokers appeared to balance withdrawal symptom alleviation and taste and enjoyment factors in the hypothetical choice to purchase electronic cigarettes, and lower nicotine content cartridges were valued the most. After a two week period of use, nicotine-containing electronic cigarettes were reported to reduce craving more than non-nicotine cartridges, and were used more over this period. A combination of withdrawal symptom alleviation and taste and enjoyment factors predicted both simulated demand after brief, first-time exposure and short-term electronic cigarette use over a twoweek period.
Conclusions These studies demonstrate the utility of psychological and behavioural economic methods for contributing to tobacco control research. The findings suggest that product characteristics that influence subjective effects and price mechanisms could increase the uptake of novel alternative products (Very Low Nicotine Content cigarettes and electronic cigarettes) to ultimately reduce cigarette smoking behaviour. The results highlight the potential for price policy and the availability of nicotine-containing electronic cigarettes to reduce smoking inequalities between New Zealand European and Maori/Pacific smokers in New Zealand. However they also suggest that the effects may be limited in isolation. Overall, price, nicotine reduction and electronic cigarette availability are likely to provide the greatest behavioural change when combined into a comprehensive nicotine and tobacco control policy that uses price differentials to encourage transitions to less harmful products, and uses the combination of nicotine reduction and electronic cigarettes to break the link between the reinforcing effects of nicotine and combustible cigarettes.