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Fig. 7.2 In agent-based modelling, the entities of the system are represented explicitly and
individually in the model. The limits of the entities in the target system correspond to the limits of
the agents in the model, and the interactions between entities correspond to the interactions of the
agents in the model (Edmonds 2001)

Thus, to summarise our thoughts in the context of the classification of modelling
approaches in the social sciences, we understand that the essence of agent-based
modelling is the individual and explicit representation of the entities and their
interactions in the model, whereas computer simulation is a useful tool for studying
the implications of formal models. This tool happens to be particularly well suited to
explore and analyse agent-based models for the reasons explained above. Running
an agent-based model in a computer provides a formal proof that a particular micro-
specification is sufficient to generate the global behaviour that is observed during
the simulation. If a model can be run in a computer, then it is in principle possible
to express it in many different formalisms, e.g. as a set of mathematical equations.
Such equations may be very complex, difficult to interpret, and impossible to solve,
thus making the whole exercise of changing formalism frequently pointless, but
what we find indeed useful is the thought that such an exercise could be undertaken,