The theoretical approach in dealing with the aggregation of information in markets in general, and financial markets in particular considers information as an exogenous element to the system, focusing just on conditions and consequences of the efficient incorporation of information into prices....

In his ‘Simple model of herd behaviour’, Banerjee (1992) shows that – in a sequential game – if the first two players have chosen the same action, all subsequent players will ignore their own information and start a herd, an irreversible one. The points of strength of Banerjee’s model...

Kirman’s “ant model” has been used to characterize the expectation formation of financial investors who are prone to herding. The model’s original version suffers from the problem of N-dependence: its ability to replicate the statistical features of financial returns vanishes once the...

Simulations of agent-based models have shown that the stylized facts (unit-root, fat tails and volatility clustering) of financial markets have a possible explanation in the interactions among agents. However, the complexity, originating from the presence of non-linearity and interactions, often...