The representation of the individual in economics as a rational homo oeconomicus had been seriously questioned by the development of behavioural economics. Some authors nevertheless argue that economists do not need to produce complex models of human behaviour, since such investigation does not fall within the scope of economic analysis. We show that the mere definition of the scope of economic analysis is quite ambiguous, between on the one hand a conception of economics as a science of individual choice and on the other hand as a science of social institutions: this duality finds its origins during the marginalist revolution with Jevons, Menger and Walras, whose theories seem to be in conflict concerning the scope of economic analysis and the definition of the "economic man". Economists then produced two distinct models of this economic man, one as the simplification of a real individual, and the other as a representative agent. The figure of the homo oeconomicus developed later by Pareto homogenized these two traditions, leading to the indeterminacy of the scope of economic analysis and in fine to the development of behavioural economics. Since behavioural and neoclassical economics are the continuation of these two distinct traditions, we stress that they should be considered as complementary rather than substitute approaches to economic analysis.
Reconciling behavioural and neoclassical economics