システム情報系　社会工学域　　　　　　　　　　　　　　　　　　　　　　　　    

         平成27年度　　ファカルティ・セミナー

                       (Faculty Seminar)

日　時　：　2015年7月30日(木)　　16：30-18：00

場　所　：　第三学群F棟　3F1119

講演者　：　岩�ｱ　康平（いわさき　こうへい）[一橋大学大学院経済学研究科]

司会者　：　石川　竜一郎

演　題　：　Random Serial Dictatorship and Externalities

                           ＜ 概要 ＞

This paper considers the problem where we assign indivisible goods to agents with lotteries and without money. The random serial dictatorship has been a common method for real-life problems such as the assignment of university housing. This mechanism only elicits agents' preferences over indivisible goods. However, it would be natural to consider the situation where each agent cares also the goods to be allocated to the other agents. In that situation, how does the mechanism work? Moreover, how do the agents report their preferences to the mechanism designer? To incorporate such externalities, we assume that the agents' preferences are over ``deterministic assignments.’’ We show that the agents' dominant strategies must be reporting the ``deduced'' preferences from the preferences over deterministic assignments, and that all the deduced preferences are dominant strategies exactly when the preferences over deterministic assignments are ``order preserving.'' It turns out that if each agent has order preserving preferences, the mechanism has the properties that are satisfied in the model without externalities.