Int. J. Environ. Res. Public Health 2011, 8 1689 estimated would be biased toward the null. More detailed SES measures may be needed to fully understand the relationship of SES and cessation with use of price minimizing behaviors. 6. Conclusions The estimates presented in this paper indicate that the availability of lower priced cigarette alternatives may attenuate public health efforts aimed at reducing smoking prevalence through price and tax increases. The relatively high availability of lower cost tobacco products may result in alternative options to cessation in people who may have otherwise quit in the wake of increasing cigarette prices. This paper also shows that high use rates of price minimizing behaviors (simultaneous use of sources) was associated with an even lower likelihood of cessation outcomes compared to only using one source. Additionally, long term use of low and untaxed sources resulted in consistently lower rates of cessation indicators at long-term follow-up. However, the results of this paper suggest that there is no interaction present between price minimizing behaviors and SES on cessation outcomes. Therefore, policies aimed at eliminating or reducing the price differentials or availability of less expensive alternatives should be equally effective among individuals with varying socio-economic levels. Acknowledgements Funding: Major funders of multiple surveys were: National Cancer Institute, US P50 CA111326)(P01 CA138389)(RO1 CA 100362) (R01 CA125116); Canadian Institutes of Health Research (57897 and 79551), National Health and Medical Research Council of Australia (265903 and 450110), Cancer Research UK (C312/A3726), Robert Wood Johnson Foundation (045734), and Canadian Tobacco Control Research Initiative (014578), with additional support from the Centre for Behavioural Research and Program Evaluation, National Cancer Institute of Canada/ Canadian Cancer Society. None of the sponsors played any direct role in the design and conduct of the study; the collection, management, analysis and interpretation of the data or the preparation, review, and approval of the manuscript. Ethics clearance: The study protocol was approved by the institutional review boards or research ethics boards of the University of Waterloo (Canada), Roswell Park Cancer Institute (United States), University of Strathclyde (UK), University of Stirling (UK), The Open University (UK), and The Cancer Council Victoria (Australia). References 1. 2. 3. Jha, P.; Chaloupka, F.J. Curbing the Epidemic: Governments and the Economics of Tobacco; The World Bank: Washington, DC, USA, 1999. Levy, D.T.; Cummings, K.M.; Hyland, A. Increasing taxes as a strategy to reduce cigarette use and deaths: Results of a simulation model. Prev. Med. 2000, 31, 279-286. Chaloupka, F.J.; Warner, K.E. The Economics of Smoking. In Handbook of Health Economics, 1st ed.; Culyer, C.J., Newhouse J.P., Eds.; Elsevier: Amsterdam, The Netherlands, 2000; Volume 1, pp. 1539-1627.