Agent-Based and Population-Based Modeling of Trust Dynamics

Trust is usually viewed at an individual level in the sense of an agent having trust in a certain trustee. It can also be considered at a population level, in the sense of how much trust for a certain trustee exists in a given population or group of agents. The dynamics of trust states over time can be modelled per individual in an agent-based manner. These individual trust states can be aggregated to obtain the trust state of the population. However, in an alternative way trust dynamics can be modelled from a population perspective as well. Such a population-level model is much more efficient computationally. In this paper both ways of modelling are investigated and it is analyzed how close they can approximate each other. This is done both by simulation experiments and by mathematical analysis. It is shown that the approximation can be reasonably accurate, and for larger numbers of agents even quite accurate.