Efficiency Considerations in Online Auction Markets

The main contention of this article is that online auction markets are amenable to efficiency considerations akin to traditional financial markets. While the underlying assets traded are dissimilar between the financial and online auction markets, the fundamental principles that drive these markets are consanguineous in that similar efficiency notions are applicable. Based on the principles of arbitrage, we develop a set of efficiency criteria to evaluate the auction activity of new and identically described items. Two arbitrage principles, seller arbitrage and buyer arbitrage, are developed. These principles can be employed to evaluate the price behavior of temporally proximate auctions and to generate a useful benchmark to make efficiency evaluations. We find evidence of inefficiency for each of the items we empirically tested based on the data from eBay, currently the largest online auction house.