This concept is closely linked to that of bounded rationality. Rationally, and according to neoclassical economic theory, consumers know when the price of a good/service exceeds the marginal utility they gain from consuming that good/service – in this rational world of homo economicus, consumers stop consuming. In reality, though, there is plenty of evidence to suggest that consumers often do not stop consuming even when it makes sense to stop – think about over-eating, excessive investment in a particular stock or share and so on.