Many 'public health' policies aimed at reducing harmful alcohol use, such as minimum pricing, are underpinned by a belief in the Total Consumption Model. This model—also known as the Ledermann Hypothesis—says that the heaviest drinkers always consume a fixed proportion of the alcohol sold in a country. Therefore, to reduce the consumption by the heaviest drinkers, the total amount of alcohol consumed in the country has to be reduced. If you reduce total consumption by X per cent, alcohol-related harm will also fall by X per cent. This assumption drives neo-temperance policies that target the entire population. Essentially, it answers the old question of "why should the majority be punished for the sins of the minority" by saying "because it works."
But does it? The theory may be elegantly simple, but the real world frequently refuses to abide by it. In the UK, alcohol consumption has fallen by 16 per cent in the past decade without having an impact on alcohol-related hospital admissions. A graph from a recent report from the Centre for Social Justice illustrates the lack of correlation.
Admittedly, hospital admissions data is compromised by the NHS constantly expanding the definition of an alcohol-related admission, but new evidence from Australia also undermines the Total Consumption Model. As in Britain, per capita alcohol consumption has been falling in Australia for some years but alcohol-related harm has continued to rise. It now transpires that the heaviest drinkers have been drinking even more while total consumption has been falling.
From the Herald Sun:
'Australia's binge drinkers have graduated into super binge drinkers consuming more than 3090 standard drinks a year.
This equates to 38 litres of alcohol a year - nearly four times the Australian average of 10 litres of alcohol a year.
Ten years ago binge drinkers were drinking 3000 standard drinks a year now they are drinking an extra 90 standard drinks a year - and half the alcohol consumed in Australia is drunk by the top 10 per cent of drinkers.
This explains why even though nationally the average amount of alcohol consumed has declined there are more hospitalisations, alcohol ED presentations and cirrhosis of the liver cases.
While most of us have been cutting back what we drink, the heavy drinkers have been making up for this by increasing what they drink.'
This is clearly inconsistent with the Total Consumption Model, but total consumption is a poor indicator of alcohol-related harm. The graph below shows alcohol consumption amongst different socio-economic groups in the UK as measured by occupation. (A-C: Managerial and professional, D-E: Intermediate, F-H: Routine and Manual.)
The wealthiest groups (A to C) consume the most alcohol while the poorest groups consume the least. We might therefore expect rates of alcohol-related mortality to be highest amongst the wealthiest groups and lowest amongst the poorest groups. In fact, the pattern of alcohol-related death goes in the opposite direction, with the group that drinks the least having the highest rate while the group that drinks the most has the lowest rate.
No sensible person would look at the inverse correlation between consumption and harm shown in these two graphs and conclude that the answer is to get the poorest group to drink more. We know that group averages contain extremes. The poorest group contains many people who drink heavily and many people who do not drink at all. The best approach would be to target those who are drinking very heavily rather than trying to adjust the average.
There is no obvious reason why patterns of heavy drinking and alcoholism should be influenced by the habits of the median drinker. It is well known that moderate drinkers are more responsive than dependent drinkers to price rises and educational campaigns. The problem with broad, population-based temperance policies is that they reduce consumption amongst those who are not drinking at harmful levels while neglecting those who have a genuine drinking problem.
Tackling alcoholism is not easy and rather than get their hands dirty dealing with the heaviest ten per cent of drinkers, politicians and 'public health professionals' prefer to target the entire population. The effect has been to create a class of the 'worried well' who are responsive to these policies and a class of hardened drinkers who are not.
In Australia, the penny seems to have dropped, at least with the researcher who conducted the study mentioned above:
"Overall consumption has dropped but harms have increased. This new evidence about the divergence in habits between heavy and light drinkers goes some way to explaining the apparent contradictions... we need to think about interventions that focus on heaviest drinkers rather than just the whole population."