Auction design is hot. The Economist reports on 4G auction design in the UK: The government will want to squeeze as much revenue as it can from the sell-off, but it must also preserve competition in a consolidating industry. The recent merger of Orange and T-Mobile has left Britain with four mobile-phone operators: Everything Everywhere (the imperious name for the newly merged company), Vodafone, O2 and Three. That is a healthy number compared with some countries, such as America, where AT&T’s proposed acquisition of T-Mobile USA would create what some regard as, in effect, a duopoly. But Three warns that it would struggle in an unrestrained bidding war with its larger rivals for the new spectrum.