Agent-based modelling. History, essence, future

The currently fashionable modelling tool agent-based simulation is characterized. The first part concerns the past. It presents a selection of the major intellectual roots from which this new tool emerged. It is important for social scientists, in particular for economists, to see that two relevant impacts came from neighbouring disciplines: biology and network theory. The second part concerns the present of ABM. It aims at highlighting the essential features which are characteristic for an agent-based model. Since there are currently several different opinions on this topic, the one presented here also includes some more epistemologically oriented ideas to support its plausibility. In particular the notion of emergence is scrutinized and extended. This part ends with a short recipe stating how to build an agent-based model. In the last part some ideas on the future of agent based modelling are presented. This part follows the sequence of syntax, semantics, and pragmatics. The syntactic challenges, like operators for pattern recognition, will be meat by a continuing variety of software packages and programming languages tailored to support ABM. The semantic aspect of future agent-based modelling hinges on the close relationship between the tool ABM and its object of investigation, e.g. evolutionary political economy. The need to model institutional change or communication processes will imply adaptive evolution of ABM. The pragmatics of future agent-based modelling are finally characterized as the most demanding – but also as the most influential – element that the new tool will bring about