Auctions have been used to sell goods and services for thousands of years. Records of Babylonian slave auctions date back to 500 B.C. The famous auction houses of Sotheby’s and Christie’s began in the 1700s and continue to be successful by specializing in the sale of rare works of art. Research on the economics of auctions did not flourish until auctions became a more common way of selling goods and services. Research interest rose when the U.S Government decided to auction off the right to drill for offshore oil in the 1970s. Beginning in the 1990s, the government auctioned off radio spectrum for use by cell phone providers. In the last 15 years, growth of the Internet has made Internet auctions feasible. Internet auctions have lowered the cost of bringing sellers together with potential buyers who may be scattered around the globe. Today, millions of people participate in Internet auctions for awide range of items such as consumer collectables, clothing, electronic equipment, automobiles, and real estate. As auctions became a more common way of doing business, economic theorists have worked to identify auctions that are Pareto efficient and are the most profitable for sellers. The proliferation of sales by auction has generated more data, making it possible to empirically analyze buyer and seller behavior and the efficiency of real auctions. The articles in this series address a number of important issues on the economics of auctions. The first paper by Kevin Hasker and Robin Sickles contains a survey of the auctions found on eBay, the leading Internet auctioneer in the world. eBay’s behavior is interesting in general, as it uses several selling formats besides auctions. In addition, eBay auctions are not consistent with all of the formal bidding rules of