Abstract

This model allows to study how the existence and structure of relations of epistemic trust in a group of truth-seeking agents might affect the epistemic performance of the agents taken individually and as a group. At each step, each agent independently receive from nature a noisy signal pointing to the real value of a certain parameter in [0,1], and balance this information with indirect information about the parameter he obtains by observing the beliefs of his trusted fellows. Agents are taken to be boundedly rational and update their belief following a version of DeGroot model of update (also known as Lehrer-Wagner rule). The agents' abilities to extract information from nature can be differentiated between expert abilities and laymen abilities. These abilities can in turn be varied in the model, in the form of a variation of the standard deviation of the normal law followed by the random signals that experts and layman respectively receive from nature as indication pointing to the real value of the parameter. The structures of epistemic trust can be choosen amongst 4 possibilities : a so-called "master" structure, an "observer" structure, an "circle" structure and a form of random structure which can be used for control purposes in experiments. Epistemic performance is measured as the distance of the believed value to the true value of the parameter.