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The societal value of moral behaviour

There is overwhelming empirical evidence that people are neither consistently selfish nor consistently altruistic. Instead, their public-spiritedness depends on their contexts. This column provides an integrative framework for thinking about the context-dependence of moral values. It gives useful insights for understanding how people behave in addressing their existing collective action problems and provides guidelines for how people ought to apply moral principles in response to new collective action problems.

There is overwhelming empirical evidence that people are not consistently selfish, along the lines of Homo economicus. Nor are they consistently altruistic. Instead, their public-spiritedness depends on their contexts. People are more likely to help strangers during crises (Rodriguez et al. 2006). They are more likely to act altruistically when they feel empathy for another person (Batson et al. 1997). Moral principles such as the golden and silver rules tend to be prioritised in particular religious and cultural settings (Norenzayan and Shariff 2008).

Furthermore, people often adhere to moral values that may be in conflict, but their application of these values is context-dependent. Moral dilemmas frequently arise from such conflicts (Haidt and Joseph 2004). Moral decision making often depends on the political context, with conservatives emphasising authority and loyalty and liberals focusing on harm and fairness (Jost et al. 2009). Evolutionary science suggests that Homo sapiens have had such evolutionary success because they have managed to adapt their collective action to their ever-changing collective challenges (Henrich 2016, Wilson 2015).

Our recent paper (Fleurbaey et al. 2023) provides an integrative framework for thinking about the context-dependence of moral values, building on other contributions (e.g. Tabellini 2007, Brekke et al. 2003). It gives useful insights for understanding how people behave in addressing their existing collective action problems and it provides guidelines for how people ought to apply moral principles in response to new collective action problems.

In the paper, we present a functionalist explanation of moral motives. Moral motives induce people to cooperate in the pursuit of common goals and to suppress destructive competition. A motive is conceived in psychological terms as a force that gives direction and energy to one's behaviour, influencing the objective of the behaviour. Moral motives are understood as motives associated with right or wrong actions or with good or bad outcomes, primarily within a social context. We conceive of moral motives as forces supporting our collective interests. Moral incentives are the psychic benefits and costs arising from the moral motives.

The key point about moral motives is that they change actions away from those that would emerge with a purely self-interested objective towards those that advance group objectives. It is as if there were a self-imposed Pigouvian tax or subsidy (named after the British economist A.C. Pigou, who first analysed systematically how taxes can correct for negative externalities and subsidies can do so for positive externalities). Moral motives are a social, not a monetary, method for encouraging socially beneficial actions and restraining socially damaging ones.

The interpretation of morality as a self-imposed tax or subsidy allows a clear analysis of the components and motivations for changing individual behaviour in the collective interest. Let us illustrate this with the problem of provision of a public good in a two-person society. Each person chooses to supply an input (say, of time) to the public good (say, community organisation). This time input is translated into effective input through a differing productivity coefficient for each individual (some people are inherently better community organisers than others). The two effective contributions are then summed to produce a total community output, and this total enters the utility of both individuals – a true public good. However, this public good is valued differently by the two individuals.

Start with the case where both individuals are entirely selfish. They do not take into account the benefit to the other person (a positive externality) of their own contributions to the public good. Not surprisingly, this lack of coordination will lead to an undersupply of the public good. But exactly how much should each individual contribute to the public good if the objective is the wellbeing of the group, defined as a weighted sum of the two selfish individuals’ wellbeing? These adjustments to the individual efforts towards the public good can be worked out, and it can be shown that they correspond to how individuals would have behaved when selfish, had they self-imposed a subsidy (because this is a positive externality) on themselves. This subsidy rate, different for each individual, is a measure of the moral adjustment needed to convert selfish behaviour to be completely aligned with group wellbeing.

What does this subsidy rate, this moral adjustment, depend upon? As should be clear from the reasoning above, it depends on three parameters of the problem as set out: the relative productivity of the two individuals in producing the public good, their relative valuation of the public good, and the relative weight of their selfish utility in group wellbeing. Each of these considerations can be linked to major strands of the moral philosophical literature.

We show first that the greater the productivity of an individual producing the public good, the greater should be the self-imposed subsidy, i.e. the greater should be the moral incentive, to contribute more to the public good. This relates to long standing religious precept that “From everyone who has been given much, much will be demanded” (Luke, 12:48). In other words, “from each according to his ability”. Second, we show that the greater an individual’s need for the public good, the greater should be the moral incentive for the other individual to contribute to the public good. In other words, “to each according to his need”. Third, we show that the greater the social weight on the wellbeing of an individual, the greater the moral adjustment needed (the greater the self-imposed subsidy) for the other individual. The weighting can itself be underpinned by a variety of moral values on distributive justice – the Rawlsian social objective function, for example, would focus on the worst-off individual, putting the burden of moral adjustment on this count entirely on to the better-off individual.

These results are striking, since they stand in contrast to much conventional moral reasoning. For instance, it is common to depict the morality of merit (reward people in accordance with their abilities) as being opposed to the principle of need (reward people in accordance with their needs). Moreover, the principle of distributive justice is commonly viewed as quite separate from the principles of need or merit. The results above, however, suggest that these various moral principles should be combined in the appropriate proportions for socially optimal outcomes to be achieved. The diverse moral principles underlying the diverse moral motives are to be understood not as mutually exclusive alternatives, but as components to be applied in combination with one another.

Our basic framework can be modified, extended, and applied in a number of different directions. For example:

  • What if individuals differ in the weights they give to each other in arriving at group wellbeing? Then the moral adjustments thought appropriate by each in a full optimum could differ in general. However, analogously to results on taxation starting from zero taxation, starting from zero morality there will be agreement on a marginal increment of morality to a positive level. Beyond this, however, there will come a point when one individual will want more moral adjustment than the other. A more homogeneous set of distributional weights will better elicit agreement, leading to a theory of group formation clustered around similar moral precepts.
  • Consider the situation where technical progress has a differential impact on individuals’ capacities to produce the private good with the endowment left over after contributing to the public good. Insofar as technological progress falls primarily on the better-endowed individual, we show that, for enhanced group wellbeing, that technological progress should be accompanied by an ongoing rise in the richer individual's moral responsibility for contributing to the public good and an ongoing fall in the poorer individual's moral responsibility for such contributions.
  • In situations where individual contributions to the public good are not simply additive (as in total time provided to a community project) but are complementary (as when individuals bring different skills to a common project), then we can rationalise the  principle of moral reciprocity (the silver rule): each individual has a moral incentive to reciprocate the other individual's contribution to the relationship, weighted in accordance with morally relevant factors.

Our research has major policy implications. If, as our analysis suggests, people are morally load-bearing, then the question of whether monetary tax-subsidy incentives crowd out or crowd in moral motives (e.g. Benabou and Tirole 2006, Bowles 2016) should be recognised as an ever-present problem. Furthermore, policymakers often influence the contexts in which people make their moral decisions. Examples include urban policy (affecting physical and social contexts) and education policies (such as whether academic performance is evaluated with regard to individual or group merit). Finally, the ubiquity of moral motives calls into question that neoliberal division of responsibilities, whereby consumers maximise their own utility, businesses maximise their profits, and the government designs rules of the game to promote efficiency and equity. Instead, government policy should design rules that promotes the moral capabilities of civil society and business.


Batson, C D, N Ahmad and J A Tsang (2002), “Four motives for community involvement”, Journal of Social Issues 58(3): 429-445.

Benabou, R and J Tirole (2006), “Incentives and prosocial behavior”, American Economic Review 96(5): 1652-1678.

Bowles, S (2016), “Moral sentiments and material interests: When economic incentives crowd in social preferences”,, 26 May.

Brekke, K A, S Kverndokk and K Nyborg (2003), “An economic model of moral motivation”, Journal of Public Economics 87(9-10): 1967-1983.

Fleurbaey, M, R Kanbur and D Snower (2023), “An Analysis of Moral Motives in Economic and Social Decisions”, CEPR Discussion Paper 18682. 

Haidt, J and C Joseph (2004), “Intuitive ethics: How innately prepared intuitions generate culturally variable virtues”, Daedalus 133(4): 55-66.

Henrich, J (2016), The Secret of Our Success, Princeton University Press.

Norenzayan, A and A F Shariff (2008), “The origin and evolution of religious prosociality”, Science 322(5898): 58-62.

Rodriguez, H, J Trainor and E L Quarantelli (2006), “Rising to the challenges of a catastrophe: The emergent and prosocial behavior following Hurricane Katrina”, The Annals of the American Academy of Political and Social Science 604(1): 82-101.

Tabellini, G (2007), “Morality matters for economic performance”,, 22 December.

Wilson, D S (2015), Does Altruism Exist?, Templeton Press.