2.2.4 Departures from rationality
The assumption that people act rationally (that is, maximize their expected utility) represents a core pillar of economic thought that allows economists to derive “optimal” behaviour in a normative sense. Models of rational behaviour can also explain and predict actual behaviour. It is as fundamental an assumption as the “reasonable person” is within the application of the law. Most economists would not approve dismissing the rationality assumption altogether, not least because doing so would open the way to paternalism in a broad range of areas, under the pretext of “helping people do what is best for themselves”.