Exploring feedback and endogeneity in agent-based models

Agent-based modeling is an approach used to describe systems composed of autonomous, independent, interactive, and potentially adaptive agents. Although agent-based models (ABMs) often include endogenous relationships that exist in agent-level interactions, such relationships are seldom salient when the structural elements of the models are analyzed and communicated. There are close relationships between agent-based modeling and other systems modeling techniques, such as the system dynamics approach. In system dynamics, feedback effects among major model components that can rapidly take systems far from equilibrium states are central to the modeling approach. In this paper we distinguish between structural endogeneity and behavioral endogeneity in models and derive an explicit representation of feedback and endogeneity in agent models-agent feedback diagrams. Finally, we describe a way that endogeneity and feedback may be highlighted in agent-based modeling and simulation.