Taking the Lab to the Field: Experimental Tests of Alternative Mechanisms to Procure Multiple Contracts

The first part of the paper reports the results from a sequence of laboratory experiments comparing the bidding behavior for multiple contracts in three different sealed bid auction mechanisms; first-price simultaneous, first-price sequential and first-price combinatorial bidding. The design of the experiment is based on experiences from a public procurement auction of road markings in Sweden. Bidders are asymmetric in their cost functions; some exhibit decreasing average costs of winning more than one contract, whereas other bidders have increasing average cost functions. The combinatorial bidding mechanism is demonstrated to be most efficient. The second part of the paper describes how the lab experiment was followed up by a field test of a combinatorial procurement auction of road markings.Multiple units, non-constant costs, asymmetric redemption values, alternative procurement mechanisms

Spectrum Auction Design

Spectrum auctions are used by governments to assign and price licenses for wireless communications. The standard approach is the simultaneous ascending auction, in which many related lots are auctioned simultaneously in a sequence of rounds. I analyze the strengths and weaknesses of the approach with examples from US spectrum auctions. I then present a variation, the package clock auction, adopted by the UK, which addresses many of the problems of the simultaneous ascending auction while building on its strengths. The package clock auction is a simple dynamic auction in which bidders bid on packages of lots. Most importantly, the auction allows alternative technologies that require the spectrum to be organized in different ways to compete in a technology-neutral auction. In addition, the pricing rule and information policy are carefully tailored to mitigate gaming behavior. An activity rule based on revealed preference promotes price discovery throughout the clock stage of the auction. Truthful bidding is encouraged, which simplifies bidding and improves efficiency. Experimental tests and early auctions confirm the advantages of the approach.Auctions, spectrum auctions, market design, package auction, clock auction, combinatorial auction

The Clock-Proxy Auction: A Practical Combinatorial Auction Design

We propose the clock-proxy auction as a practical means for auctioning many related items. A clock auction phase is followed by a last-and-final proxy round. The approach combines the simple and transparent price discovery of the clock auction with the efficiency of the proxy auction. Linear pricing is maintained as long as possible, but then is abandoned in the proxy round to improve efficiency and enhance seller revenues. The approach has many advantages over the simultaneous ascending auction. In particular, the clock-proxy auction has no exposure problem, eliminates incentives for demand reduction, and prevents most collusive bidding strategies.Auctions, Combinatorial Auctions, Market Design, Clock Auctions

Bidder support in iterative, multiple-unit combinatorial auctions

This thesis is about supporting the bidders' decision making in iterative combinatorial auctions. A combinatorial auction refers to an auction with multiple (heterogeneous) items, in which bidders can submit bids on packages. Combinatorial auctions are challenging decision making environments for bidders, which hinders the adoption of combinatorial mechanisms into practice. Bidding is especially challenging in sealed-bid auctions. Bidders do not know the contents of other bidders' bids and hence cannot place bids that would team up with existing bids to become winners. The objective of this study is to develop and test support tools for bidders in semi-sealed-bid, iterative combinatorial auctions. The tools are designed for reverse auctions, but can easily be applied to a forward setting. The Quantity Support Mechanism (QSM) is a support tool, which provides the bidders with a list of bid suggestions. The bid suggestions are such that if submitted, they would become provisional winners. The QSM benefits both bidders and the buyer, because it chooses suggestions that are most profitable for the bidders while decreasing the total cost to the buyer. The QSM is based on a mixed integer programming problem. The QSM was tested in two simulation studies. The results of the studies indicated that the QSM works well - it is much better to use the QSM than no support - but that it does not necessarily guide the auctions to the efficient allocation. The QSM was also integrated into an online auctions system, and tested with human subjects. The results of the laboratory experiment showed that the performance of the QSM is dependent on the bidders' behavior and the kind of bids they place in the auction. The user interface of the auction was good. I also observed bidders' strategies, and could identify different bidder types corresponding to those reported in earlier studies. The experiment also showed the importance of experience in complex bidding environments. The simulation studies and the laboratory experiment showed that the QSM is too dependent on the existing bids in the bid stream, which causes the auctions to end in inefficient allocations. In order to overcome this problem we designed another support tool, the Group Support Mechanism (GSM). The main logic in the GSM is similar to the QSM. The main difference is that instead of solving for one bid that complements existing bids to become a winner, the GSM can suggest several bids for different bidders. Together this set of bids would then become provisionally winning. The preliminary tests show significant improvement in the efficiency of the auction outcomes when the GSM was used instead of the QSM. Future research includes the further development of the GSM and its testing with simulations and human subjects. Also, bidder behavior, bidder strategies and the effect of learning and experience in combinatorial auctions should be further studied. This is important because bidders' behavior in the auctions affects the auction design and the requirements for the user interface