Morality: evolutionary foundations and policy implications

Since the publication of Adam Smith’s Wealth of Nations, it has been customary among economists to presume that economic agents are purely selfinterested. However, research in experimental and behavioral economics has shown that human motivation is more complex and that observed behavior is often better explained by additional motivational factors such as a concern for fairness, social welfare etc. As a complement to that body of work we have carried out theoretical investigations into the evolutionary foundations of human motivation (Alger andWeibull 2013, 2016). We found that natural selection, in starkly simplified but mathematically well-structured environments, favors preferences that combine self-interest with morality. Roughly speaking, the moral component evaluates one’s own action in terms of what would happen, if, hypothetically, this action were adopted by others. Such moral preferences have important implications for economic behavior. They motivate individuals to contribute to public goods, to give fair offers when they could get away with cheap offers, and to contribute to social institutions and act in environmentally friendly ways even if their individual impact is negligible. “Act only according to that maxim whereby you can, at the same time, will that it should become a universal law.” [Immanuel Kant, Groundwork of the Metaphysics of Morals, 1785] ∗Toulouse School of Economics, CNRS, and Institute for Advanced Study in Toulouse †Stockholm School of Economics, Institute for Advanced Study in Toulouse, KTH Royal Institute of Technology, and Toulouse School of Economics ‡This paper was presented at the conference “The State of Economics, The State of the World”, at the World Bank, June 8-9, 2016. It will appear as a chapter in a MIT Press book with the conference title, under editors Kaushik Basu, David Rosenblatt, and Claudia Sepulveda (Fall 2017). The authors thank Daniel Chen, Jean-François Laslier, Assar Lindbeck, Erik Mohlin, Paul Seabright, Jean Tirole, Nicolas Treich, Yu Wen, and Peter Wikman for valuable comments and suggestions.