A Practical Guide to the Combinatorial Clock Auction
The combinatorial clock auction (CCA) is an important recent innovation in auction design that has been utilised for many spectrum auctions worldwide. While the theoretical foundations of the CCA are described in a growing literature, many of the practical implementation choices are neglected. In this article, we examine some of the most critical practical decisions for a regulator implementing the CCA. Topics include: implementation of reserve prices; endogenous band plans; supplementary round activity rules; competition policy; bidding languages; and allocation of the core burden. We illustrate our discussion with examples from recent spectrum auctions that used the CCA format.