From this failure to expunge the microeconomic foundations of neoclassical economics from post-Great Depression theory arose the microfoundations of macroeconomics debate, which ultimately led to a model in which the economy is viewed as a single utility-maximizing individual blessed with perfect knowledge of the future.Fortunately, behavioral economics provides the beginnings of an alternative vision of how individuals operate in a market environment, while multi-agent modelling and network theory give us foundations for understanding group dynamics in a complex society. These approaches explicitly emphasize what neoclassical economics has evaded: that aggregation of heterogeneous individuals results in emergent properties of the group, which cannot be reduced to the behavior of any representative individual. These approaches should replace neoclassical microeconomics completely.
~ Steve Keen