Evaluating the Health Impacts of Food and Beverage Taxes
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Several jurisdictions are now imposing taxes on food and beverages to prevent obesity (and related conditions). Existing evidence concerning their effects comes largely from simulation studies and trials in closed settings, both of which have limitations. Rigorous evaluation of actual taxes may provide richer evidence with greater external validity to support policy making. This article describes existing evaluation studies and outlines an implicit underlying theoretical framework for how taxes are expected to affect health. It then explores three important issues for future studies: selection of an appropriate evaluative perspective (comparing realist and biomedical experimental paradigms); approaches to causal inference; and the challenge of a low signal-to-noise ratio. We argue that evaluation should be informed by a realist perspective as well as making appropriate use of established empirical quasi-experimental approaches to testing causal effects. This should be underpinned by a theoretical framework that acknowledges complexity and the potential diversity of impacts.
KeywordsFood Beverages Tax Evaluation Obesity
We acknowledge Ian Shelmit for his constructive comments on our thinking in this area.
Compliance with Ethics Guidelines
Conflict of Interest
Helen Eyles received grants from Heart Foundation of New Zealand and Health Research Council of New Zealand.
Oliver T Mytton and David Ogilvie declare that they have no conflict of interest.
Human and Animal Rights and Informed Consent
This article does not contain any studies with human or animal subjects performed by any of the authors.
Papers of particular interest, published recently, have been highlighted as: • Of importance
- 1.Mytton OT, Clarke D, Rayner M. Taxing unhealthy food and drinks to improve health. BMJ Br Med J. 2012;2931(May):1–7.Google Scholar
- 3.Academy of Medical Royal Colleges. Measuring up: the medical professions’s prescription for the nation's obesity crisis. London; 2013.Google Scholar
- 8.Shemilt I, Marteau TM, Smith RD, Ogilvie D. Biting off more than we can chew? Limitations in the use of modelling to inform policy on food tax and subsidy. Press.Google Scholar
- 9.Mytton O, Clarke D, Rayner M, Mytton OT. Taxes on unhealthy food and drinks. 2012;2931(May):1–7.Google Scholar
- 11.Boseley S. Mexico enacts soda tax in effort to combat world’s highest obesity rate. Theguardian.com. 2014.Google Scholar
- 12.Pipe S. St Helena shows UK the way with fizzy drinks tax. St Helena Online 2014. http://sthelenaonline.org/2014/03/28/st–helena–sho.
- 13.Sustain. A children’ s future fund. London; 2012.Google Scholar
- 14.FIZZ - Fighting sugar in softdrinks. http://www.fizz.org.nz/.
- 15.Brunner J. Mayor McGinn suggest soft-drink tax for parks money. The Seattle Times. 2013.Google Scholar
- 16.Kearney L. California city tests waters for soft drinks tax. Reuters. 2014.Google Scholar
- 17.Beesley A. Reilly sought 20 % tax on sugary drinks in Budget, records who. The Irish Times. 2014.Google Scholar
- 20.Consultation on standardised packaging of tobacco products. https://www.gov.uk/government/news/consultation-on-standardised-packaging-of-tobacco-products.
- 21.Pawson R, Tilley N. Realistic evaluation. London: Sage; 1997.Google Scholar
- 24.Bahl R. The uneasy case against discriminatory excise taxation: soft drink taxes in Ireland. Public Financ Rev. 2003;31. doi: 10.1177/1091142103253753.
- 26.Faculty of Public Health. A duty on sugar sweetened beverages. London; 2013.Google Scholar
- 27.Landon J, Graff H. What is the role of health-related food duties? London; 2012.Google Scholar
- 32.Briggs ADM, Mytton OT, Kehlbacher A, Tiffin R, Rayner M, Scarborough P. Overall and income specific effect on prevalence of overweight and obesity of 20 % sugar sweetened drink tax in UK: econometric and comparative risk assessment modelling study. BMJ. 2013;347:f6189.PubMedCentralPubMedCrossRefGoogle Scholar
- 34.•Petticrew M, Anderson L, Elder R, Grimshaw J, Hopkins D, Hahn R, et al. Complex interventions and their implications for systematic reviews: a pragmatic approach. J Clin Epidemiol. 2013;66:1209–14. A discussion fo complexity within public health interventions and its implications for evaluation of interventions, with a particular focus on how to piece together information from different studies in diffferent contexts.PubMedCrossRefGoogle Scholar
- 36.•Jensen JD, Smed S. The Danish tax on saturated fat – Short run effects on consumption, substitution patterns and consumer prices of fats. Food Policy. 2013;42:18–31. An example of an evaulation of an actual tax on food with the use of robust statistical techniques and consideration of appropriate confounding influences.CrossRefGoogle Scholar
- 37.Berardi N, Sevestere P, Tepaut M, Vigneron A. The impact of a “soda Tax” on prices: evidence from French micro data. Paris; 2012.Google Scholar
- 42.Butland B, Jebb S, Kopelman P, McPherson K, Thomas S, Mardell J, et al. Foresight Tackling Obesities: Future Choices. London; 2007.Google Scholar
- 44.Craig P, Cooper C, Gunnell D, Haw S, Lawson K, Macintyre S, et al. Using natural experiments to evaluate population health interventions: guidance for producers and users of evidence. London: MRC; 2011.Google Scholar
- 45.Humphreys DK, Panter J, Sahlqvist S, Goodman A, Ogilvie D. A framework for considering exposure in place-based natural experimental studies in public health. Press.Google Scholar