We do not yet understand the psychological mechanisms explaining how cigarette pack size affects smoking, let alone smoking cessation.

Abstract

We do not yet understand the psychological mechanisms that explain how cigarette pack size impacts upon smoking and smoking cessation. The field of food consumption and obesity provides useful insights through research on portion size and its associations with value for money and unit bias. The idea to limit the number of cigarettes in a pack is a neglected area in tobacco control. Blackwell et al.’s paper 1 is important, as it puts the issue firmly on the policy agenda. The increasing availability of larger pack sizes, with up to 50 cigarettes per pack in some countries, is disturbing and threatens to undermine national tobacco control policies, particularly taxation. The authors advise that governments limit the number of cigarettes to 20 per pack, the same amount as the minimum in many countries, including the United States and members of the European Union. Because this is a neglected research area, the authors base their advice mainly on indirect evidence and the assumption that limiting the number of cigarettes will lead to reduced smoking and more smoking cessation. The question is, of course, whether or not we know enough to recommend this policy. There are other regulatory options to consider. For example, one strategy might be to set a fixed price per cigarette to suppress price competition, much like the fixed book price in some countries. The authors are absolutely right to emphasize the need for experimental research to study causal relationships between pack size and smoking cessation. We argue that other types of research are also called for to begin to understand why a limit on pack size is a sensible regulatory measure and what limit is most effective. Most importantly, we need to understand the psychological mechanisms through which changes in the number of cigarettes per pack affect product use and appeal. The authors only consider reduced smoking as a mechanism. There is much to be learned from the field of food consumption and obesity, where portion size has been studied for the past two decades. There are two main factors which can explain why people take larger portion sizes than they actually need 2, 3. The first is the notion of ‘value for money’: consumers get a lower price per unit. We hypothesize that this might be the main mechanism in smokers, and tobacco companies have applied this strategy to offset tax increases or retain consumers who are at risk of switching to value brands 4. However, price sensitivity might compete with other motivations such as convenience and appeal. For example, tobacco industry marketeers know that large packs potentially detract from perceived quality 4. The second mechanism is ‘portion distortion’, where people feel that a specific portion size is an appropriate amount to consume. One factor relevant in portion distortion might be particularly relevant for smokers. This is ‘unit bias’, which is ‘a sense that a single entity is the appropriate amount to engage, consume or consider’ 5. Smokers are used to smoking a pack of cigarettes within a specific time unit, such as 1 or 2 days. If a larger size becomes the new norm, we would expect them to, unconsciously, smoke more. Another mechanism might be availability: the larger the stock, the more one consumes, as it takes longer before one has to go out to buy new supply. There is some evidence that smokers regulate consumption in accordance with pack size 6, such that smaller packs may help quitting smoking 7. A first step to disentangle the psychological mechanisms is through qualitative research exploring smokers’ considerations for buying packs with few or many cigarettes. It is important to talk with smokers from various age groups. For example, young smokers might prefer larger packs as better value, but they might also think they are uncool, associating them with heavy, addicted, older smokers. Another avenue is to conduct discrete choice experiments (DCEs). These would be very helpful to shed light on the question of which subgroups of smokers respond in which manner to which changes in attributes of cigarette products. DCE also allow pack size to be studied alongside price, brand image, convenience, appeal, taste and other attributes related to consumer choice behaviour. In any case, the topic should be an international research priority, as larger and larger packs continue to flood the market. None.