Imitation and Learning under Uncertainty: A Vignette Experiment

Existing theories regarding effects of social networks on trust problems stress the influence of information about behavior of potential partners in the past and possibilities to sanction untrustworthy others in the future. Effects of imitation are less extensively elaborated in the literature. In this paper, we develop a theory about (rational) imitation in combination with other network effects on trust. We introduce a distinction between imitation and other types of learning based on whether trustors know that a trustee has been trustworthy, or only that other trustors have been trustful in transactions with this trustee. The theory predicts that imitation as well as learning has effects in trust situations. In addition, both imitation and learning are predicted to become more important if the trustor is more uncertain about various aspects of the focal trust problem. We designed a vignette experiment that enables us to distinguish between imitation and learning for different levels of uncertainty. The effects of learning and imitation find empirical support but the association of the strength of the effects with uncertainty is only partially supported by the results of the experiment. Useful suggestions and comments by Werner Raub, Jeroen Weesie, Chris Snijders, Ronald Batenburg, and Tom Snijders are gratefully acknowledged. This paper is part of the research program “Management of Matches” funded by the Netherlands Organization for Scientific Research (NWO) under grant PGS 50-370. Buskens’ contribution is part of the project “Third-party effects in cooperation problems” of the Royal Netherlands Academy of Arts and Sciences (KNAW).