Discussion

Given equal effectiveness, financial incentives, whether rewards or penalties, are judged as less acceptable than medical interventions. We found this across five different health contexts and in participants from the UK and US. There are two possible sets of explanations for these findings. The first set assumes that these are valid results: participants based their judgements on the stated assumption that the financial and medical interventions were equally effective, and perceive incentives as less acceptable. This raises two questions: first, what explains these attitudes? Second, would incentives be seen as more acceptable if they were more effective, or would people refuse to make such trade offs? There are several possible reasons why people may find financial incentives less acceptable. It may stem from a violation of a cultural norm, namely the use of money in the relationship between a doctor or healthcare provider and a patient. Much has been written about areas of life in which money is an acceptable form of exchange and those in which it is not, these boundaries varying across time and between cultures.14–17 The perceived unacceptability of financial incentives in the current context may also stem from a marked sense of injustice about offering money, a fungible good, to those who, through their own behaviour, might have avoided this. Concerning the nature of the incentive, it is possible that incentives that are less exchangeable (eg, vouchers or vouchers prespecified only for exchange of goods related to improved health) may be more acceptable.

We found differential support for penalties over rewards depending on the context of the basic treatments. We found only limited evidence that this related to perceptions of responsibility. It is plausible that our question about responsibility tapped different constructs for the different medical conditions. For example, notions of responsibility for being addicted to drugs are plausibly tied more closely to moral judgement and attributions of blame than are notions of responsibility for a knee injury. Evidence exists that some health behaviours, such as cigarette smoking, can become ‘moralised’,18 19 potentially linking responsibility with personal blameworthiness.

The second set of explanations for these findings is that they are not valid that is, they do not represent people's true views. This may be because the manipulations did not work as intended. For example, although we had instructed participants to assume that all interventions were equally effective in improving outcomes, it is possible that participants did not accept this assumption, resulting in perceived differences in effectiveness explaining differences in perceived acceptability. Respondents may simply believe that different interventions were differing in effectiveness, based on their own ‘prior probabilities,’ even if told that this was not so.

Replication and extension of the current study is needed to allow a more robust examination of the acceptability of financial incentives, using named as well as unnamed conditions, experimentally varied to assess the extent to which the acceptability of incentives is influenced by cost, effectiveness, perceived responsibility as well as type of reward (cash or vouchers for general or prespecified use).

Rejection of incentive schemes by the general public could all too easily be seen by politicians as a reason not to introduce them. This conclusion does not follow from our findings. To answer the question as to whether or not incentive schemes should be introduced would require more evidence on their consequences, intended and unintended, as well as in-depth analysis of the associated ethical issues of using incentives in healthcare. Perceptions about the acceptability of incentives, especially if accompanied by strong feelings, can be seen as a consequence,20 but the basis for such judgements are not fully understood. It may be the case that the results reported here stem from prejudice and illegitimate value judgements, and should thus not be reflected in policy decisions. For example, it is not clear how stable the preference for medical over financial interventions really is ‘taboos’ of using money in some contexts vary across cultures and may well change over time.14 As noted above, rejection of incentives may be based on beliefs about effectiveness or about unintended consequences, beliefs that can be challenged by evidence. Acceptance of different schemes may be subject to framing and presentation, or to personal experience, all of which vary and can be influenced. Even if a residual disutility for incentives in health contexts stubbornly persists, benefits may be great enough to justify overriding such concerns. At the other extreme, opposition to ‘rewarding bad behaviour’ might translate into the very tangible consequence of corroding the goodwill, and eroding the good behaviour, of those not rewarded for their virtue.

We note that ‘acceptability’ is a rather problematic concept. What we have not presented here is a survey of attitudes to incentives, which would inherently be time and context bound, sensitive to changes in salient background, such as exposure to recent news reports of incentive schemes or direct participation in such a scheme. Nevertheless, ‘acceptability’ is in some sense a relational property linking the incentive, the health behaviour, the respondent's attitudes and beliefs, and the wider context. And, as noted, acceptability is not inherently a normative concept that can be mapped directly onto right and wrong, fair or unfair. Nevertheless, the findings here presented do give some clues as to how experimentally informed evaluations of the fairness and moral rightness or wrongness of incentive schemes could be developed further, and of how the supposedly timeless intuitions of philosophers about these matters may be improved by the use of experimental studies.