Twee Engelse onderzoekers onderzochten op een unieke manier de effecten van rookverboden op de blootstelling van niet-rokers aan tabaksrook. Hun conclusies zijn verrassend: door roken overal op publieke plaatsen en in de horeca te verbieden en geen alternatieve plaatsen van bij elkaar komen aan te bieden wordt een tegengesteld effect bereikt. Doordat rokers gaan roken op andere, minder gewenste plaatsen (volgens de onderzoekers), worden niet-rokers juist méér en intensiever blootgesteld aan tabaksrook!
En wat nog meer bijzonder is: het zijn juist de kinderen die, doordat rokers minder uitgaan en daarom thuis bezoek ontvangen en meer roken, meer aan omgevingsrook worden blootgesteld.
The effect of passive smoking is of increasing public concern. Although the economic literature has evaluated the effect of government intervention on smoking intensity or prevalence, there has been, so far, no direct evaluation of these measures on non-smokers.
In this paper we characterize the extent of exposure to environmental smoke, and evaluate the effect of changes in excise taxes and bans on passive smoking. We use a direct measure of passive smoking which has not been used in the economic literature, the concentration of cotinine, a metabolite of nicotine, in body fluids of non smokers. This allows us to precisely identify the effect of state intervention on non-smokers.
We find that increasing taxes on cigarettes reduces on average exposure to cigarette smoke of non smokers. The effect of state excise taxes also varies across demographic groups. We find that taxes have a strong effect on young children living with smokers but no effect on non smoking adults. This suggests that smokers cut down on the cigarettes they smoke at home but not those in social activities with other adults.
Using information on the implementation of the Clean Air Act across time and different US states, we also find that smoking regulations have on average no effect on exposure. We show that this latter result is not due to a lack of statistical power to detect a precise effect but rather to the fact that regulations have contrasting effects depending on where they are imposed and depending on which group of the population is affected. While bans in public transportation, shopping malls, and schools lead to the desired decrease in exposure of non smokers, 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 in small children considerably increases as a result of bans in recreational public places, while decreases if tighter bans are put in place in public transport or shopping malls.
A third and important finding is that smoking regulations increases exposure of poorer individuals, while it is beneficial to individuals in higher socio-economic position. The rise in the number of regulations observed over the nineties is likely to have increased health inequalities related to passive smoking.
Our results question the usefulness of bans in reducing smoking exposure for non smokers. More precisely, we show that policies aimed at reducing exposure to tobacco smoke induce changes in behaviors which can offset these policies. It is therefore of crucial importance to understand how smoking behaviors are affected by regulations. So far, the literature has not gone far enough in studying smoking behavior to be able to evaluate their effect on non smokers. It is not enough to show that smokers react to prices or taxes. Information on which particular cigarette is cut down during the day, where smokers smoke and with whom are also relevant. There are complex interactions at play and considerable heterogeneity in their effects across socio-demographic groups. Using a biomarker such as cotinine concentrations is a very direct way of evaluating the overall effect of interventions and the induced changes in behaviors.
On the policy side, it seems therefore important when designing public policies aimed at reducing tobacco exposure of non smokers to distinguish between the different public places where bans are introduced. Displacing smoking towards places where non-smokers live is particularly inefficient. It may also increase health disparities across socio-economic groups and in particular in children. Therefore, total bans may not be the optimal policy. A better policy may be to allow for alternative places to which smokers can turn to. It would benefit children but harm non smoking adults. There are several reasons why one may want to protect children. They constitute a vulnerable group with little choices to avoid contamination. This age group is particular prone to tobacco related diseases and poor health in childhood has lasting consequences not only for future health but also for the accumulation of human capital (Case et al, 2005).
Governments in many countries are under pressure to limit passive smoking. Some pressure groups can be very vocal about these issues and suggest bold and radical reforms. As often, their point of view is laudable, but too simplistic in the sense that they do not take into account how public policies can generate perverse incentives and effects. Up to know there is little guidance on how to design optimal policies to curb passive smoking. This paper fills this gap.