Auctions with Untrustworthy Bidders

The paper analyzes auctions which are not completely enforceable. In such auctions, economic agents may fail to carry out their obligations, and parties involved cannot rely on external enforcement or control mechanisms for backing up a transaction. We propose two mechanisms that make bidders directly or indirectly reveal their trustworthiness. The first mechanism is based on discriminating bidding schedules that separate trustworthy from untrustworthy bidders. The second mechanism is a generalization of the Vickrey auction to the case of untrustworthy bidders. We prove that, if the winner is considered to have the trustworthiness of the second-highest bidder, truthfully declaring one's trustworthiness becomes a dominant strategy. We expect the proposed mechanisms to reduce the cost of trust management and to help agent designers avoid many market failures caused by lack of trust.

Access Rights Inheritance in Information Systems Controlled by Metadata

All information systems have to be protected. As the number of information objects and the number of users increase the task of information system’s protection becomes more difficult. One of the most difficult problems is access rights assignment. This paper describes the graph model of access rights inheritance. This model takes into account relations and dependences between different objects and between different users. The model can be implemented in the information systems controlled by the metadata, describing information objects and connections between them, such as the systems based on CASE-technology METAS.