Intended for healthcare professionals

Rapid response to:

Observations Alcohol and Public Health

Costs of minimum alcohol pricing would outweigh benefits

BMJ 2014; 348 doi: https://doi.org/10.1136/bmj.g1572 (Published 19 February 2014) Cite this as: BMJ 2014;348:g1572

Rapid Response:

Re: Costs of minimum alcohol pricing would outweigh benefits

In his response to the BMJ’s ‘Under the Influence’ series, Christopher Snowdon makes a series of misleading and inaccurate claims regarding the evidence base pertaining to minimum unit pricing (MUP) for alcohol. Many of his claims repeat critiques of the Sheffield Alcohol Policy Model which Snowdon expressed in a report co-authored with John Duffy, a scientist who acted as a paid consultant for the Scotch Whisky Association during its legal challenge against MUP [1]. Although Snowdon claims his arguments have “simply not been answered”, we actually produced a detailed rebuttal of Duffy and Snowdon’s critique in January 2013 [2]. Given Snowdon has ignored its arguments, we wish to take this opportunity to briefly restate the relevant points.

Firstly, Snowdon argues that: “If social scientists tell a computer that a minimum price will reduce licit alcohol consumption and that, more controversially, this reduction will lead to better health outcomes, it is self-evident that the computer will reflect this in its estimates of ‘lives saved’”. This is a misrepresentation of how the Sheffield Model works. The key inputs driving the model’s results are not the subjective decisions of researchers but, as is appropriate, published evidence on the purchasing patterns of UK drinkers [3] [4], evidence on the impact of price changes on those purchasing patterns [5] and evidence on the epidemiological relationship between drinking and risk of harm [6]. We have published extensive sensitivity analyses demonstrating how alternative data, evidence sources and analytical methods affect model results. The baseline data is updated periodically and we have adapted the model to other contexts to ascertain how policy effectiveness may respond to changing baseline conditions [7-9]. All of this work is in the public domain and accessible to all interested parties.

Snowdon’s second major point relates to the challenges of evidence-based policy-making. He argues: “the evidence is partial because the models are partial” and “Economic decisions involve trade-offs. If public health academics wish to make a serious contribution to an economic debate, they must recognise this”. We have, in fact, stressed throughout our work that no model can capture all aspects of a complex reality and all of our publications follow good scientific practice by discussing the main limitations of our analyses [3] [4] [10]. Snowdon’s ability to assess these limitations is a product of our transparency. We also agree that policy decisions must strike a compromise between competing interests. Our rebuttal of Snowdon’s previous critique acknowledges this: “The judgment as to whether the wider evidence base and the modelling is reliable enough to enable policy makers to… implement MUP falls within a complex public process of debate involving academic peer review, political judgment and scrutiny, and commentary and consultation with the public and stakeholders holding a range of worldviews and vested interests.”

Thirdly, Snowdon claims that MUP is regressive and will penalise those on low incomes. We have recently published a detailed equity-focused appraisal of MUP which shows this argument to be simplistic [3]. As moderate drinkers with low incomes buy very little alcohol sold for less than the proposed 45p per unit threshold, the effect on them will be negligible. In contrast, alcohol purchases made by heavy drinkers with low incomes will be substantially affected. However, as this is the group at greatest risk of harm due to their drinking, they also stand to accrue the greatest health gains from the policy. We estimate approximately 80% of the health benefits of MUP would accrue to those in routine or manual worker households and the long-term unemployed – a clearly progressive outcome. Any judgement on the equity of MUP should take this more nuanced assessment into account.

Finally, Snowdon takes issue with our claim that: “[The Sheffield Alcohol Research Group] can’t really change the narrative in any way – we don’t have that power – but bodies such as the Adam Smith Institute have this public megaphone which is disproportionate to the scientific merits of what they’re saying”. While we agree that researchers can and do influence the narrative, our chief frustration is not with our own contribution but with our critics’ engagement in ‘scientific debate’. This is exemplified by Snowdon and his co-author, John Duffy. In October 2012 the Scottish Government asked us to comment on a critique of the Sheffield Model produced by Duffy and submitted as part of the Scotch Whisky Association’s legal challenge against MUP. Our detailed rebuttal was submitted to the court. In November 2012, Duffy and Snowdon published their critique for the Adam Smith Institute which contained similar arguments and made no attempt to engage with our rebuttal [11]. Again, we published a detailed response in January 2013 [2]. In April 2013, Duffy published a third critique in the newsletter Significance which presented variations on the same arguments without any acknowledgment of our previous responses [1]. As a scientist, we would expect Dr Duffy to display good scholarship in three ways: firstly by referencing our responses to the critiques so readers are aware of relevant work; secondly by responding to the rebuttals rather than repeating similar or the same criticisms and, thirdly, by submitting his arguments to the peer-reviewed journals which published our original work (The Lancet and Addiction). To our knowledge, he has refrained from engaging on all three counts.

We believe the public health community should welcome contributions to policy debate from those with alternative worldviews as this is conducive to a well-functioning democracy. However, we also believe those contributions should follow two principles: first they should acknowledge the full range of available evidence and, second, they should engage reasonably in the dialectic argument rather than ignoring already public rebuttals and repeating previously dismissed claims. The BMJ’s Under the Influence series and other research has highlighted how the alcohol industry fails on the first principle due to its biased and selective use of evidence [12]. Snowdon’s response to the BMJ fails on the second principle. Given the high profile of the BMJ’s investigation and the commentaries that have followed, we believe that it is untenable for Snowdon or Duffy to present again their misleading claims about our work without referencing and engaging with the existing rebuttals.

John Holmes
Petra S. Meier
Robin C. Purshouse
Alan Brennan

Reference List

(1) Duffy JC. The price of a drink - too exactly? Flawed evidence for minimum unit pricing. Significance 2013; 10(2):23-27
(2) Brennan A, Purshouse R, Holmes J, Meng Y. A public response to the Adam Smith Institute's critique of the Sheffield Alcohol Policy Model. 2013. Sheffield, University of Sheffield.
(3) Holmes J, Meng Y, Meier PS, Brennan A, Angus C, Campbell-Burton CA et al. Effects of minimum unit pricing for alcohol on different income and socioeconomic groups: a modelling study. Lancet 2014;
(4) Purshouse RC, Meier PS, Brennan A, Taylor KB, Rafia R. Estimated effect of alcohol pricing policies on health and health economic outcomes in England: an epidemiological model. Lancet 2010; 375(9723):1355-1364
(5) Meng Y, Brennan A, Purshouse R, Hill-MacManus D, Angus C, Holmes J et al. Estimation of own and cross price elasticities of alcohol demand in the UK: A pseudo-panel approach using the Living Costs and Food Survey 2001-2009. J Health Econ 2014; 34:96-103
(6) Corrao G, Bagnardi V, Zambon A, La Vecchia C. A meta-analysis of alcohol consumption and the risk of 15 diseases. Prev Med 2004; 38(5):613-619
(7) Hill-MacManus D, Brennan A, Stockwell T, Giesbrecht N, Thomas G, Zhao J et al. Model-based appraisal of alcohol minimum pricing in Ontario and British Columbia: A Canadian adaptation of the Sheffield Alcohol Policy Model Version 2. 2012. Sheffield, University of Sheffield.
(8) Meng Y, Purshouse R, Brennan A, Meier P. Model-based appraisal of alcohol minimum pricing and off-licensed trade discount bans in Scotland using the Sheffield Alcohol Policy Model (v2): An update based on newly available data. 2010. Sheffield, University of Sheffield.
(9) Meng Y, Brennan A, Holmes J, Hill-MacManus D, Angus C, Purshouse R et al. Modelled income group-specific impacts of alcohol minimum unit pricing in England 2014/15: Policy appraisals using new developments to the Sheffield Alcohol Policy Model (v2.5). 2013. Sheffield, ScHARR, University of Sheffield.
(10) Purshouse, R., Brennan, A., Lattimer, N., Meng, Y., Rafia, R., Jackson, R., and Meier, P. Modelling to assess the effectiveness and cost-effectiveness of Public health related strategies and interventions to Reduce alcohol attributable harm in England using the Sheffield Alcohol Policy Model version 2.0. Report for NICE. 2009.
(11) Duffy JC, Snowdon C. The Minimal Evidence for Minimum Pricing: The fatal flaws in the Sheffield Alcohol Policy Model. http://www.adamsmith.org/blog/liberty-justice/the-minimal-evidence-for-m...
(12) McCambridge J, Hawkins B, Holden C. Industry use of evidence to influence alcohol policy: A case study of submissions to the 2008 Scottish Government consultation. PLos Medicine 2013; 10(4):e1001431

Competing interests: No competing interests

21 March 2014
John Holmes
Research Fellow
Petra S. Meier, Robin C. Purshouse, Alan Brennan
ScHARR, University of Sheffield
30 Regent Street, Sheffield, S1 4DA