An Automated Negotiating Protocol That Adjusts the Negotiation Order based on Pre-Negotiations

Abstract

Automated negotiations have been studied very widely. Usually, in the field of automated negotiations, researchers focus on bilateral negotiations, in which two agents negotiate for each other. One-to-one bilateral negotiations are more natural in the real world among companies compared with a market-style (one-to-many). In the real world, companies are doing multiple bilateral negotiations every day. However, there is less research on multiple bilateral negotiations. Some mathematical analysis was conducted in the case of 3 agents in the classic economic literature, and also there has been a proposed protocol called SAOP for multiple bilateral negotiations in the international competition, ANAC. In multiple bilateral negotiations, the results may differ greatly depending on the order in which the bilateral negotiations are conducted. However, in previous research on the automatic negotiation protocol between multiple agents, which has been conventionally used in international competitions, almost no research considering the negotiation order was found. Therefore, in this study, we investigated whether better negotiation results could be obtained by using a proposed protocol that dynamically determined the negotiation order. The better negotiation result described here means that the value of the social surplus, which is the sum of the acquired utility values of all the negotiation agents, is high and has the shortest possible time. The method proposed here is social surplus-based pre-negotiation (hereinafter referred to as“ pre-negotiation”), in which the agent who evaluates the most important issues in a multi-agent negotiation starts the negotiation first. In this study, we compared the values of social surplus, the number of agreements, and negotiation time for 3, and 6-agent negotiations against the proposed and conventional methods. The results showed that the protocol proposed in this study achieved the highest social surplus, especially when pre-negotiation was used, and the protocol was more effective as the number of agents participating in the negotiation increased.