The dynamic dimension of these models is more abstract than in the previously described types because here one time step is considered over when every cell has had the possibility to change its state. In order to analyse local economic competition, the state of a cell might gives the conditions of a specific production site. Producers with decision rules defined ex ante can move over this grid in order to find the best production site for themselves. Furthermore, every agent potentially constitutes an element of the environment for every other agent. An agent is usually represented by a self-contained program, so that action parameters and decision rules have to be defined ex ante .
Computational agents have to be distinguished from economic or social agents.
The number of these two agent types can differ in a model because various economic agents may be represented by only one computer agent, i.e., a computational agent defines only the functional form for the decision rules of economic agents in the case where individuals of a population have identical decision rules defined ex ante . These agents differ only in respect of their ability to process information. While one individual decides to do something, another one does not, because the latter agent has a poorer ability to process information than the former. Models of this kind are described in chapter 9. So far, all the types of models discussed have defined the decision rules of the agents ex ante .