Drugs – Without the Hot Air: Minimising the Harms of Legal and Illegal Drugs
Paperback, 368 pages, ISBN: 9781906860165, published 31 May 2012
In 2009, Professor David Nutt was rather unceremoniously asked by the then home secretary, Alan Johnson, to step down as the chairman of the Advisory Council for the Misuse of Drugs (ACMD). Nutt had had numerous clashes with Johnson and his predecessor Jacqui Smith over his comments comparing the risks associated with recreational drug use. In particular, Nutt compared the risks of ecstasy use with that of horse riding, claiming ecstasy use was much safer. Many people claimed that they were incomparable; apples and oranges. But we often rely on simple metrics to evaluate the risks posed by different activities. If I asked you whether you think bungee jumping was a good idea or not, you would want to know how often harm or death befalls someone who does it. This is what Nutt did with horse riding (1 adverse event every ~350 exposures) and ecstasy (1 adverse event ~10,000 exposures).
Nutt claimed his dismissal was political, Johnson claimed Nutt was being political by commenting on policies. In this instance it is likely Nutt was right. Our preconceived, moralistic ideas about drug use bias our evaluations of its safety. If I fell off of my horse and got a concussion but then, once better, tried again to tame that wild horse that bucked me, you might think me admirable. However, if I took some ecstasy and collapsed from dehydration after dancing too much, but then went back and took more ecstasy the following week, you might think me a fool. Anyway, the point is that we need to adopt a rational approach to policy making when it comes to controversial topics such as these.
After his dismissal, Nutt went on to form the Independent Scientific Committee on Drugs (ISCD). Recently he published Drugs, a book detailing his research and that of others on recreational drugs as well as a discussion about the costs and benefits of drug policy. Costs? Benefits? Is it an economic work? You might well ask. Well, it isn’t, but it contains a wide range of ideas familiar to the economist and uses them to identify the problems of current policy. Here, I want to go over those ideas and articulate them using a bit more econspeak.
One of the key ideas in the book is that policy makers confuse prevalence with harm. Policies regarding recreational drug use should aim to minimise harm but they currently focus on reducing prevalence. When we appraise an intervention for the treatment of a disease we look to see its overall benefit in terms of increasing quality adjusted life years, not how many people can benefit from it (although the two may be related). By enforcing prohibition and providing the disincentive of prison for drug taking you do reduce the prevalence of drug use. But who are those that refrain from taking it?
When we discuss the response of demand to changes in price we talk about the elasticity of demand, which is calculated as the slope of the demand curve for a particular good. However, this slope can be very different depending on where along the curve you are. Studies have found that addicts’ demands for hard drugs are very inelastic (i.e. do not change in response to a price change), whereas first-time and recreational users of soft drugs have very elastic demand. Therefore, increasing the pecuniary and non-pecuniary costs to the user via a policy of prohibition will put off those with elastic demand but not those with inelastic demand. But it is the addicts that commit the most crime; addiction treatment has been shown to have a causal effect in reducing crime, and it is the addicts that are most at risk of adverse health consequences. The policy reduces prevalence but not harm.
Nutt discusses the idea of substitute goods, without actually using those words, and talks about the idea of a marginal rate of substitution between two drugs. Specifically, he mentions mephedrone; also known as plant food or MCAT. A synthetic drug, it was available legally via the internet and its use peaked in 2010. The newspapers widely reported it and its adverse effects, wrongly attributing a number of deaths to it (in fact mephedrone was only found to have contributed to 2 deaths). In 2010 mephedrone was made a class B drug in the United Kingdom. Mephedrone produces similar effects to amphetamine, MDMA and cocaine, and as such is a substitute for them. The prohibition of mephedrone reduced its supply in the United Kingdom, and approximately quadrupled its price, and as a result cocaine use increased. It is thought that the policy of making mephedrone illegal actually caused a number of deaths from cocaine use.
For many health economists, accurately comparing the costs and benefits of different health interventions is their bread and butter. Using a wide range of evidence to put two, often different, things on the same scale to allow policy-makers to make comparisons. But, as many people are aware, policy-makers can often be swayed by emotive arguments and personal prejudices. Certain groups lobby on behalf of different diseases to overturn decisions about drug reimbursement. In a previous post I argued that prohibition, as a policy (for drugs or other things, such as asbestos), is costly and is not cost-effective by any measure. In Drugs, Nutt compares the arguments against cannabis use, such as that it is a ‘gateway’ drug or causes mental health issues, with prison. He argues that the risks of cannabis use are much less severe than the harms caused by prison. He mentions that 7% of heroin users first tried heroin in prison whereas in the Netherlands, where cannabis use is decriminalised, heroin use is among the lowest in Europe. Approximately 1 in 5,000 cannabis users may go on to develop schizophrenia; in prison, 40% of male, and 60% of female, inmates suffer from some form of neurotic disorder.
Drugs is a simple book, presenting the key facts and arguments, and is often a defence by Nutt of many of his well reported statements. Perhaps by dispensing with technical language and explaining the facts clearly, policy-makers may sit up and take note.