In 1936, the American social scientist Robert Merton wrote an article in which he attempted to formalise what social scientists have long understood, but activists, policymakers and politicians have either ignored or denied. Merton argued that both individual and government actions have effects that are unforeseen, unintended and all too frequently unwelcome.

According to Merton, the most common unintended consequences result from ignorance and error. However, he also found that many perverse consequences flowed from what he called the ‘imperious immediacy of interest’ – where a group or government wants something so much that they deliberately ignore or deny the unintended negative effects.

Instances of unintended consequences are legion. Many economists, for example, have argued that government-provided old age pensions, while helping to reduce poverty amongst the aged, have also resulted in individuals saving much less for their retirement years precisely because they believe that the ‘government will take care of them’.

The recent North American experiment in extending summer time by three weeks in order to save energy is another instance of unintended consequences. According to energy analysts, the extra hour of evening daylight has increased the amount of driving – because of the longer evenings – and this in turn increased, rather than decreased, overall energy consumption.

With the public smoking ban that was enforced in England and Wales on 1 July, there are several signs that the smoke-free English pubs and restaurants that are supposed to be a boost for public health instead might increase the risks to non-smokers.

That is because smokers displaced from one of the last public places to allow smoking will likely increase their smoking at home. According to a study by Jerome Adda and Francesca Cornaglia of University College London (The Effect of Taxes and Bans on Passive Smoking, 2006), there are a number of unintended and perverse consequences associated with a countrywide public smoking ban.

Using information from the US National Health and Nutrition Examination Survey (NHANES III), which is a sample of over 50,000 individuals, Adda and Cornaglia found that smoking bans resulted in what they called a ‘perverse displacement of smoking’ from public places such as pubs and restaurants to residential settings, which were more likely to have children present.

Instead of reducing their smoking in a uniform manner, smokers confronted with workplace, pub, and restaurant smoking bans, smoke less in these places but in turn increase their smoking at home. According to Adda and Cornaglia, public smoking bans have in general ‘no effect on exposure’ for non-smokers.

As a result, children, one of the supposed major beneficiaries of public smoking bans, receive higher exposures to environmental tobacco smoke (ETS) under smoking bans than before such bans. As the authors note, ‘We find that bans in recreational public places can perversely increase tobacco exposure of non-smokers by displacing smokers to private places where they contaminate non-smokers. Children seem to be particularly affected by this displacement. The level of cotinine [a nicotine marker] in small children considerably increases as a result of bans in recreational public places.’

An increased level of smoking at home is not the only perverse consequence of a public smoking ban. Adda and Cornaglia also show that while such bans might reduce the second-hand smoke exposure of wealthier individuals, they in fact increase the exposure of poorer individuals – something that reinforces existing health disparities and works against the government’s policy of reducing health inequality.

Adda and Cornaglia suggest that the reason for this disparity is due to the ‘larger displacement effects for low-income individuals who are also more likely to live with smokers’, since the prevalence of smoking is higher in poorer families to begin with.

What this means, according to Adda and Cornaglia, is that complete public smoking bans are not smart tobacco control policy. Rather, they reflect the ‘simplistic’ and doctrinaire approach of the anti-tobacco lobby and its refusal to ‘take into account how public policies can generate perverse incentives and effects’. A much better policy, they suggest, would be one that allows for ‘alternative places to which smokers can turn to’ to avoid increased smoking at home.

Nor is greater exposure to second-hand smoke, particularly for the poor, the only unintended and perverse consequence of the upcoming smoking ban. A recent report by the insurer, Direct Line, notes that house fires will increase because of the public smoking ban. According to their calculations, almost 16million additional cigarettes will be smoked at home because of the smoking ban, placing about a million residences at increased risk from fires.

A similar increase in smoking at home, and in the consequent number of residential fires, took place in New York after the city’s public smoking ban in 2003. (Direct Line’s estimate is based on the fact that 70 per cent of the UK’s 10 million-plus smokers smoke at home. Of these seven million smokers, 15 per cent say that the smoking ban will force them to smoke more at home.) Currently, there are about 60 smoking-related house fires a week in the UK, with about 110 fatalities annually.

The anti-tobacco lobby has always argued that the precautionary principle of ‘better safe than sorry’ is the only way to deal with the supposed menace of public smoking. Blinded by Merton’s ‘imperious immediacy of interest’, it has failed to see that smoking bans are probably worse than the ill they attempt to prevent. In the end, the illusion of safety in preventing public smoking cannot protect us from being sorry.