What explains willingness to pay for smoking-cessation treatments - addiction level, quit-rate effectiveness or the opening bid?

BACKGROUND

Several countries have now passed laws that place limitations on where smokers may smoke. A range of smoking-cessation treatments have become available, many of which have documented increased quit rates. Population surveys show that most smokers wish to quit, and most non-smokers would prefer to reduce the prevalence of smoking in society. The strengths of these preferences, however, as measured by their willingness to pay (WTP), have not yet been investigated.

OBJECTIVE

This study aims to identify variables that explain variations in people's answers to WTP questions on smoking-cessation treatments.

METHODS

A representative sample of the Norwegian population was asked their WTP in terms of an earmarked contribution to a public smoking-cessation programme. A sub-group of daily smokers was, in addition, asked about their WTP for a hypothetical treatment that would remove their urge to smoke. The impact of variation in the question format (different opening bids) on stated WTP was compared with that of factors suggested by economic theory, such as quit-rate effectiveness, degree of addiction as measured by the 12-item Cigarette Dependence Scale (CDS-12), and degree of peer group influence as measured by the proportion of one's friends who smoke.

RESULTS

In both programmes, the most important determinant for explaining variations in WTP was the size of the opening bid. Differences in quit-rate effectiveness did not matter for people's WTP for the smoking-cessation programme. Addiction, and having a small proportion of friends who smoke, were positively associated with smokers' WTP to quit smoking.

CONCLUSION

Variations in WTP were influenced more by how the question was framed in terms of differences in opening bids, than by variables reflecting the quality (effectiveness) and need (addiction level) for the good in question. While the WTP method is theoretically attractive, the findings that outcomes in terms of different quit rates did not affect WTP, and that WTP answers can be manipulated by the chosen opening bid, should raise further doubts on the ability of this method to provide valid and reliable answers that reflect true preferences for health and healthcare.