Trust as the Basis of Coalition Formation in Electronic Marketplaces

Abstract

Despite the fact that social networks are ubiquitous on the Internet, only few websites exploit the potential of combining user communities and online marketplaces. Not many platforms allow users to engage in a phenomenon called "group buying" — buyers joining groups, or coalitions, to bundle their purchasing power towards sellers. We argue that this may be due to a lack of face-to-face interaction on the Internet; often, users do not know which other users to trust, which makes them suspicious of engaging in online business, in particular if many unknown other parties are involved. This situation, however, can be alleviated by leveraging the social networks of users: based on who a user knows and is connected to, a trust metric — for example, the TrustWebRank metric developed by us — can be computed to assess who else may be considered trustworthy to that user. In this paper, we build a simple agent-based model of coalition formation among agents in the setting of group buying in an electronic marketplace. In this model, agents use their trust relationships in order to determine who to form coalitions with. We show that this leads agents to experience high utility and that agents are able to learn who is trustworthy and who is not, even when they have no initial knowledge about the trustworthiness of other agents. This work may provide the foundation for a real-world application of an online coalition formation platform for e-commerce built on a social networking platform such as Facebook.

A survey on applications of coalition formation in multi‐agent systems

“…They conduct a depth‐first search to prune a subtree whenever possible. Walter 56 uses a tree‐based decision making mechanism to find a coalition of trustworthy agents. Representation scheme: Most of the researchers assume that the coalition value v(C) can be obtained in unit time using a black‐box function, but this is a strong assumption to make 28 . A concise representation scheme for CFG uses a set of rules rather than a black‐box function 130 .…”

“…They conduct a depth‐first search to prune a subtree whenever possible. Walter 56 uses a tree‐based decision making mechanism to find a coalition of trustworthy agents.…”

“…Under such circumstances, fraudster sellers may leave the marketplace as soon as they get paid and rejoin with a new identity 136 . The authors of Reference 56,82,83 used trust relationships to evaluate and form a coalition in an electronic marketplace. Unlike Breban and Vassileva, 82 in the work by Walter, 56 an initiator acts on behalf of all the other buyers in a coalition, and negotiates between the coalition and the sellers.…”

“…The authors of Reference 56,82,83 used trust relationships to evaluate and form a coalition in an electronic marketplace. Unlike Breban and Vassileva, 82 in the work by Walter, 56 an initiator acts on behalf of all the other buyers in a coalition, and negotiates between the coalition and the sellers. In the model by Walter, 56 an agent may simply form a coalition but that will incur additional costs for negotiation, bargaining and other costs.…”

“…Unlike Breban and Vassileva, 82 in the work by Walter, 56 an initiator acts on behalf of all the other buyers in a coalition, and negotiates between the coalition and the sellers. In the model by Walter, 56 an agent may simply form a coalition but that will incur additional costs for negotiation, bargaining and other costs. Therefore, an agent can randomly select a coalition or choose a coalition based on the level of trust it has on the initiator.…”