Professor Alex Stevens:

In responding to the Deputy's question, I will refer to two examples that are decades old but that are still interesting. One is from Portugal and the other is from Lambeth in South London. Generally, there is no evidence that decriminalisation has much of an effect on the illicit market. There is no particular mechanism by which decriminalisation of possession would affect the illicit market. It does not increase use or demand, so there is no evidence of increase in the size of the illicit market. On the other hand, it does not do anything to reduce the harm of the illicit market because the incentives for the high profits and the violence that sometimes goes with those high profits are not reduced either.

Let us consider the Portuguese example. Effects were observed, for example, on drug-related deaths following the range of policies Portugal introduced in 2001 on the basis of an expert committee that looked into what was then an HIV crisis among people who use drugs. People often ascribe the positive effects of the Portuguese policy, which include a dramatic reduction in HIV infections and significant reductions in drug-related deaths, to decriminalisation. Decriminalisation was obviously a significant part of that, but there was also a simultaneous increase in support not just for people who use drugs but all people suffering economic harm. There was the introduction of a guaranteed minimum income. There were significant investments in social housing as well as a dramatic increase in the number of people in opioid-substitution therapy, largely involving methadone. Those things would be expected to lead to a reduction in drug-related problems and drug-related deaths, and indeed they did. It is argued that decriminalisation was important in enabling those things to happen by not deterring people from coming forward and saying, "I've got a problem with drugs; I need help." That is a way in which the illicit market was left in place but public health harms were reduced by a combination of decriminalisation, investment in social support and treatment.

Regarding what that does to the policing of the drug market, it is interesting that one of the explicit aims was to shift attention away from low-level drug possession towards the higher end of the market. There was some concern in the Portuguese police that not being able to get hands in the pockets of low-level drug users and ask questions about who they got their drugs from would reduce its efficiency in catching high-level dealers. That did not turn out to be the case. What we saw in Portugal was a dramatic reduction in the numbers of seizures but quite a large increase in the amounts seized, suggesting that the police were successful in shifting their attention from taking small amounts of cannabis away from many people to capturing large quantities of cocaine coming into the country and supplying the European market.

There is a parallel here with the Lambeth experiment in 2001 whereby the police in Brixton in South London decided it was better to spend their limited resources on offences which were more harmful to the community than on dealing people possessing small amounts of cannabis. The explicit intention was to shift police resources to more serious offences. What was seen was indeed a reduction in offences like burglary because the police was able to divert its attention away from spending quite a lot of time talking mostly to young black men on the street about their cannabis use and to looking at other forms of crime instead. While there is not a mechanism by which decriminalisation would affect the illicit market, there is a mechanism by which one might make better use of police time by not focusing on low-level drug possession.