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of the effect is highly unlikely to be solely from outcome to exposure’. Furthermore, attentional

bias is not a problem in prospective cohort studies, as these studies assess predictor and outcome variables at different points in time. For example, the study by Henriksen et al. (2010) showed that exposure to tobacco advertisement at the point of sale predicted smoking initiation at 12 and 30 months follow-up.

As suggested by Burton et al (2011), studies that rely on self-reports of smokers describing reasons for buying cigarettes or smoking may have been biased by an effect called 'self-serving attribution'. Self-serving attribution bias refers to people's tendency to attribute positive outcomes to personal factors and negative outcomes to external factors. In the case of self-reports on the role of POS-D, some smokers may have blamed the POS-D for their purchase of cigarettes or for the fact that they smoked cigarettes (which they would have smoked anyway). Burton et al. (2011) accounted for this type of bias by not relying on smokers’ explanations for their smoking behaviour and by analysing the associations between purchase/smoking behaviour and exposure to POS-D. Their analyses were quite conservative (e.g., excluding smokers who bought tobacco in the same period and lagged-analyses); nevertheless, significant effects on smoking were found.

Consistency

The results of the studies in this systematic review were highly consistent, with nearly all studies finding a relationship between exposure to POS-D and smoking (related) behaviours. Thomson et al. (2004) did not find a relationship between banning free standing displays and purchase

attempts. Furthermore, McNeill et al. (2011) did not find significant short-term changes in youth or adult smoking prevalence following the implementation of a display ban in Ireland.

The studies were performed using a variety of designs and with diverse samples (youth, adults, smokers, non-smokers, (attempting) quitters). None of the studies were conducted in the Netherlands, several studies were performed in the USA and Australia, and relatively few were performed in western Europe (N=4).

It should be noted that countries differ with respect to restrictions on other types of advertising at the POS. For example, in the USA, tobacco marketing is allowed at the point of sale, while it is banned (e.g., New Zealand) or highly restricted (e.g., Australia) in other countries. Nevertheless, despite these differences, the results appear to be consistent across countries.

Plausibility

With increasing restrictions on other types of tobacco advertisement, tobacco displays have become one of the major channels for the tobacco industry to promote tobacco products (Quedley et al., 2008). Tobacco displays are generally accepted to be a form of advertising. However, the possibilities of tobacco promotion by means of tobacco displays seem limited compared to other types of advertising, for example, through television or the sponsoring of (sport) events. As noted by Kvaakik (2012), ’tobacco displays must be regarded as having a less powerful effect on

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purchase tobacco products, for example through slogans’. Furthermore, tobacco displays are

always placed within shops (except for tobacco machines, which may be placed outdoors or in bars/restaurants). Due to the fact that they purchase tobacco products, established smokers are expected to have the highest exposure to tobacco displays. Nevertheless, non-smokers will also be exposed to tobacco displays, as tobacco products are also sold in non-tobacco specialist shops such as supermarkets, pharmacies, and gas stations. Thus, although there are some differences

between tobacco displays and other types of tobacco advertising, tobacco displays are likely to promote smoking in a similar way, but most likely not as strongly as other types of advertising. Furthermore, it is well established that tobacco marketing promotes smoking (Lovato et al., 2011), which is also consistent with the wider marketing literature (Moodie et al., 2012). Finally, based on empirical research, several mechanisms are described in the literature to explain how tobacco displays may have an effect on smoking (related) behaviour (Lovato et al., 2011; Wakefield et al., 2006; Carter and Tiffany, 1999; Carter et al., 2006). Taken together, these findings suggest that it is plausible that tobacco displays increase smoking.

Conclusions

The highest level of evidence for an effect of banning POS-D on smoking (related) behaviour would be provided by randomised controlled trials in a ‘real life’ setting. Because this type of design is not feasible, we must rely on the results of observational studies (longitudinal and cross-sectional) and laboratory experiments. Each of these designs has its methodological limitations, particularly cross- sectional studies, which do not allow inferences on the direction of the relationship. Nevertheless, taken together, the results described in the current literature consistently suggest that exposure to POS-D is associated with smoking (related) behaviour. Studies suggest that a higher exposure to POS-D increases the likelihood of youth initiating smoking, increases consumption among current smokers, and lowers the likelihood of successful quit attempts. Tobacco displays were also found to be associated with precursors of smoking, i.e. smoking susceptibility among youth, (unplanned) purchases of tobacco and smoking perceptions, which in turn may lead to denormalisation of tobacco use. Studies that specifically address tobacco displays are relatively scarce. However, a large body of research has shown that tobacco advertising increases smoking. Because tobacco displays are in fact a type of advertisement, it is justified to consider findings on tobacco

advertisement in general as well when determining the role of tobacco displays. However, it should be noted that tobacco displays are likely to have a less powerful effect on smoking (related) behaviour. The relationship between tobacco displays and smoking (related) behaviour is plausible from a theoretical perspective and is consistent with the wider marketing literature. In line with recent expert reports on tobacco display (bans) commissioned by Norway, we therefore conclude that banning the display of tobacco products at points of sale is likely to be an effective strategy for reducing tobacco use.

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Chapter 7 Facilitators and barriers to implementing a tobacco

product display ban

Various factors may facilitate or hamper the implementation of policies aimed at reducing the visibility of tobacco products at points of sale. We will address the following issues: public opinion and support for measures regulating the display of tobacco products (§7.1), unintended

consequences for purchasing behaviour and the market (§7.2), expected economic consequences (§7.3), and store compliance with display regulations (§7.4).

7.1 Public opinion and support for measures regulating the display of tobacco products

Data from international studies show that public support for regulating the display of tobacco products in the general population is fairly high, both before and after implementation, although the support in the Netherlands seems to be weaker.

An evaluation study of the implementation of the point-of-sale tobacco display ban in Norway showed that the ban was well supported in the population (Scheffels and Lavik, 2013). Support was strongly related to smoking status, with 70% of non-smokers, 50% of occasional smokers, and approximately 30% of daily smokers supporting the ban. The majority of the respondents (62% of non-smokers and occasional smokers and 50% of daily smokers) thought that the ban would be effective in preventing individuals from taking up smoking. The expectations with regard to the effect of the ban on quitting smoking were somewhat lower, although a large group believed that the ban would make it easier to quit (55, 46, and 24% of non-smokers, occasional smokers, and daily smokers, respectively, felt the ban would help individuals to quit smoking).

McNeill et al. (2011), evaluating the removal of point of sale tobacco displays in Ireland in July 2009, found that support for the law increased among adults after implementation, from 58% just before the ban to 66% in the months after the ban.

Cross-sectional surveys among New York City smokers and non-smokers showed that a majority of the non-smokers (± 60%) and nearly half the smokers (± 40%) were in favour of keeping tobacco products out of customers’ view and were in favour of prohibiting companies from paying retailers to display or advertise tobacco products (Farley et al., 2013).

In New Zealand on 23 July 2012, a law came into effect that required all retailers to remove tobacco products from open display. Prior to this measure, displays were allowed but restricted with respect to size, composition, and placement. Whyte et al. (2014) conducted an online survey of 364 smokers and 402 non-smokers sampled from an Internet panel to investigate public support for this measure 6 months after it came into effect. The results showed that three-quarters of the sample supported the removal of cigarette and tobacco packs from view in shops, 15% opposed it and 10% had no opinion (Whyte et al., 2014). Support differed by smoking status, with support