Complex systems modelling of alcohol consumption dynamics in the British population

Excessive alcohol consumption (drinking the equivalent, roughly, of more than 2 bottles of wine every week, or more than 4 pints of beer in a single evening) is associated with a variety of harmful outcomes, to both individuals and to society. For example, people who are drunk have a higher risk of committing criminal damage, leading to victim distress, costs to the criminal justice system, and increased insurance premiums. As a result of these harmful outcomes, governments tend to want to reduce the levels of excessive drinking in society. However, in order to be confident of taking the most appropriate action, governments need to know about how alcohol consumption is changing across society, and to understand the underlying factors that are responsible for these changes. In Britain, most of the knowledge about levels of drinking comes from surveys. In most years since 1978, the residents of about 10,000 British households have been asked about their drinking behaviour. The actual households involved change every year. The surveys allow us to estimate, for example, what proportion of women aged 18-to-24 years old are drinking excessively each year. Until recently, the surveys suggested that this proportion had stayed relatively unchanged over time: the proportion of 18-to-24 year old women who drank excessively in 1988 was similar to the proportion who drank excessively in 1978, and as both groups of women got older the proportion of them who drank to excess reduced. However, over more recent surveys, the proportion of 18-to-24 year old women who drink excessively has been rising toward the proportion of excessive male drinkers in this same age group. Whilst there has been some speculation as to why this change might have happened (for example, women staying single for longer, or perceptions of increased acceptability of female drinking, or the increased availability of alcohol in supermarkets), nobody has explored these reasons scientifically or attempted to quantify what might happen next. This project aims to address the issue of why alcohol consumption is changing over time (as in the example above) using a set of ideas and mathematical tools from an academic discipline known as complex systems modelling. It will look for patterns in the survey data, and to see if these patterns are changing over time (for example, were the sort of people who were drinking excessively in 2010 the same sort of people who were drinking excessively in 1980?). It will link these patterns to wider changes and events in society (for example, the point at which supermarkets were allowed to sell alcohol on Sundays), using methods from the discipline of economics, to identify which factors might be important. These findings will then be used to explore in detail the changes in drinking behaviour by specific groups in society. The project will combine knowledge from the academic disciplines of sociology and social psychology with survey data on groups of people born in 1958 and 1970 (whose drinking has been followed over time) to see if the drinking behaviour we see in Britain as a whole can be explained by what is happening to individual people's drinking-related attitudes, intentions and behaviours as they interact with each other and grow older. The project's findings will help inform the future actions that governments may take when trying to reduce levels of excessive alcohol consumption in society.

Policies that aim to reduce the burden to society of alcohol-related harm are the focus of significant and sustained attention, both in the UK and internationally. The range of adverse social consequences of drinking is wide, covering health (where alcohol consumption is estimated to be responsible for 3.8% of global deaths), crime and anti-social behaviour, and reduced productivity. The most recent estimate for England placed the total annual economic burden at between £18.5b and £20b. At the same time, drinking is an integral part of life for many people, who may perceive both individual and societal benefits from the consumption of alcohol.
Current and planned policies being debated in the UK include: taxation and minimum unit pricing, stricter licensing regulations, and universal screening and brief intervention programmes. Policymakers are key beneficiaries of the research: at local levels (Licensing Authorities, Police Authorities, Directors of Public Health), national levels (Whitehall policy teams in the Cabinet Office, Department for Business, Innovation and Skills, Department for Culture, Media and Sport, Department for Education, Department of Health, and Home Office; and also the devolved governments in Scotland, Wales and Northern Ireland), and international levels (European Union, World Health Organisation). Those organisations seeking to influence policymaking are also beneficiaries (particularly arms-length and third sector organisations with public health advocacy roles: historically these have included Chief Medical Officers, Alcohol Concern, Institute of Alcohol Studies, Royal College of Physicians, British Liver Trust). A third set of beneficiaries will be those non-academic organisations performing alcohol policy appraisal (historically these have included the Institute for Fiscal Studies and RAND Corporation). Downstream beneficiaries of well-informed alcohol policy implementations are the public and employers, in terms of health, wellbeing, reduced opportunity costs, and economic competitiveness.
The ability of macro-level policies to target population subgroups is important to policymakers, but existing models are based on coarse, pre-defined, age/sex categories. The research will provide a much finer-grained understanding of changes in drinking within subgroups, where the definitions of the subgroups emerge from the evidence. The availability of alcohol (e.g. hours of sale or number of outlets) is believed to be an important factor affecting consumption, but specific policies to regulate availability are yet to be proposed. The research will provide an indication of how availability policies can be designed effectively by identifying the causal pathways that produce changes in drinking behaviour. Policies that affect the pricing and promotion of alcohol are in the process of design and implementation in the UK, and are attracting significant international attention. However the model-based appraisals of policy effectiveness and net benefit that are important to policy decision-making (e.g. choosing the threshold for a minimum unit price) are measured relative to a purely hypothetical scenario of stationary drinking levels. The dynamic and predictive elements of the research aims to provide policymakers with at least short-term forecasting capability, enabling more accurate estimation of the 'do nothing' policy option and a more realistic reference point for net benefit calculations.
Whilst drinking behaviour has been selected as the test bed for the proposed methods development, the techniques that emerge - and the lessons that are learned - will be useful for policy appraisal work in other areas of behaviour change. With the World Health Organisation estimating that tobacco use, high blood glucose, physical inactivity and obesity are responsible for just over one quarter of total global deaths, the potential longer-term benefits of the research in related applications is substantial.