Spliffs and butts

IN 1952, Donald Macintosh Johnson, later the Conservative MP for Carlisle, published a study entitled “Indian Hemp: A Social Menace”. Even small doses of the drug could lead to violence and mental-health problems, he fretted. More than 60 years later, politicians from all Britain’s major parties are just as worried and resist legalisation. Yet the evidence in favour of making pot legal is as persuasive as ever.

The latest research suggests Britain could profit from decriminalising cannabis. A new report from the Institute for Economic and Social Research at the University of Essex evaluates the costs and benefits of introducing a licensed and regulated marijuana market in England and Wales. The most plausible model would mimic tobacco, with direct control of the product and suppliers, a ban on advertising, and plenty of health education.

If smoking rose by 15%, savings would be made in policing and the criminal justice system, among other places. Income tax revenues could rise as some smokers would be at work, rather than in jail. Once the costs associated with things like regulating the market and medical treatment for abusers are knocked off, the overall savings could be £361m ($574m) a year. On top of this the tax gain from levies on cannabis sales could reach as much as £900m.

Legalising cannabis would yield other benefits too. Many fear that smoking pot can lead to greater consumption of other drugs—the “gateway effect”—but licensing weed would also mean fewer people involved in the illegal drugs trade, offsetting those costs. Legalisation would not be risk-free. In the authors’ most pessimistic scenario, consumption soars by 40%, with a £1.4 billion crime wave fuelling the binge. They attach little weight to this, though: drug crime is more often linked to heroin users. So even if a lot more pot was smoked, savings could still hit £400m.

One advantage of licensing cannabis is that the government would be able to control its quality. Since 2008 worries have abounded about the strength of “skunk” cannabis. Jeremy Browne, the Liberal Democrat Home Office minister tasked with monitoring other countries’ experiments with legalisation, said in December that the weed now on sale is seven to eight times more potent than in the 1960s. Others reckon it is two to four times stronger. The change is due to a shift in production. About 75% of cannabis sold in Britain today is home-grown. Cultivators want high returns for the risks involved so have switched to stronger varieties.

Despite these arguments, a change in the law looks unlikely. Politically there is little appetite, says Harry Sumnall, an expert in substance abuse and a member of the government’s Advisory Council on the Misuse of Drugs. In March the government declared that it saw no case for fundamentally rethinking Britain’s approach to drugs. Most politicians would rather leave the subject well alone. In a poll last year 75% of MPs who participated said objective debate about reform was difficult because drug policy is so contentious.

Nor are they under much pressure from the public. According to the 2010 British Social Attitudes Survey, 58% of Britons think cannabis should remain illegal. Just 4% think it should be legalised without restriction, and 34% say it should be legalised but sold only in licensed shops. Those views are more liberal than in 1993, when 67% said it should be banned, but less so than 2001 when only 46% thought so.

And there are fewer users to push for reform. Cannabis use in England and Wales has been falling for the last decade despite the fact that inflation-adjusted prices have fallen slightly (see chart). The drop in use may in part be due to the increased potency. Many find skunk unpleasant but the gentler stuff is difficult to buy. People are more aware of potential risks to health. And the fast pace of modern life may make cannabis’s dopey effects less appealing.