Auction Design for the Allocation of Emission Permits in the Presence of Market Power

To the extent that emission permits have been allocated using market mechanisms, this has been done using a sealed-bid auction design, typically with discriminatory prices. However, several authors have recommended the ascending auction format. Basically, two competing ascending auction designs have been suggested, the standard ascending auction (with clock or demand schedules), or an alternative ascending-clock implementation of Vickrey-pricing. The latter design was introduced as a response to problems of bid shading under the sealed-bid and the standard ascending auction format. The purpose of this paper is to investigate the allocation of permits under these two alternative mechanisms. The auction process and the resulting market outcome in the presence of oligopolistic competition are simulated. In this setting, it is not obvious that bid shading is the optimal strategy under the standard design, nor is it obvious that sincere bidding is the optimal strategy under the alternative ascending auction design. The alternative auction format makes it less costly to pursue a strategy to increase market shares through the acquisition of emission permits, thus increasing the competitor's costs, leading to overbidding as the optimal strategy.