How Much Is a Dollar Worth? Tipping versus Equilibrium Coexistence on Competing Online Auction Sites
通过eBay和雅虎拍卖的实地实验，发现价格和买卖比例不符合均衡理论，市场存在倾斜现象，eBay价格比雅虎高20-70%，且每卖家多吸引两个买家。
Theory models of platform competition predict that prices and buyer-seller ratios should be approximately equal on coexisting auction sites. Using field experiments on eBay and Yahoo Auctions, we find evidence that is inconsistent with equilibrium hypotheses and suggest that the market is tipping. Prices on eBay are consistently 20-70 percent higher than those on Yahoo, and eBay attracts two additional buyers per seller. On Yahoo, prices and bidders counts are unaffected by the auction ending rule. Various differences between the sites cannot account for the magnitude of these disparities. However, a model of imitation dynamics can rationalize our findings. (c) 2009 by The University of Chicago. All rights reserved.