引入一口价拍卖机制能够改善网络交易效率吗?——理论推导与来自eBay二手车拍卖的经验证据

Can Buy-it-Now auction improve the online transactional efficiency:Theory and evidence from second-hand motors on eBay

随着互联网经济迅速发展,网络拍卖逐渐兴起,但目前国内网络拍卖主要采用纯拍卖形式,尚未引入一口价拍卖机制。本文从网络拍卖交易效率视角考察了引入一口价拍卖机制的合理性。基于动态贝叶斯博弈模型,从理论上证明了在多个同质商品竞争拍卖的现实网络交易环境中,一口价拍卖相对纯拍卖能够提高商品成交概率和卖方期望收益,从而改善网络交易效率。进而采用eBay网站二手车拍卖的经验数据,通过构建结构方程模型并利用极大似然估计法进行实证检验,结果与理论预期一致。在国内电子商务和在线交易迅速发展的背景下,有必要丰富和完善网络交易的定价机制,特别是在网络拍卖中引入一口价拍卖机制。

With the rapid development of the Internet economy, online auction is becoming popular. In addition to adopting the traditional auction mechanism in online transactions, many international online transaction platforms adopt the Buy-it-Now auction by adding a Buy-it-Now price mechanism in the auction. Domestic online auction mechanism mainly adopts pure auction, while Buy-it-Now auction has not yet been introduced to the online transaction platform. It has important theoretical and practical significance to discuss whether the incorporation of Buy-it-Now price into auction mechanism, compared to the pure auction, can improve the online transaction efficiency. In another word, whether the design of the Buy-it-Now auction mechanism is conducive to the seller and the buyer to reach a deal and raise the sellers’ expected return. The existing literature on network auction mostly adopt the classical model assuming monopoly seller to sell a single commodity and ignoring the competitive auction environment and products mismatch which results in transaction inefficiency. From the perspective of transactions probability and the seller's expected revenue, this paper studies the effect of Buy-it-Now price mechanism on network transaction efficiency with theoretical model and empirical test. Based on dynamic Bayesian game model, this paper discusses the influence of Buy-it-Now auction on the online auction transaction efficiency under the assumption of a single seller selling multiple products or multiple sellers selling products respectively. The results of theoretical derivation suggest that Buy-it- Now auction would reduce commodity mismatch in the competitive situation with a number of homogeneous products auctions in order to raise transaction probability and increase the seller’s expected revenue, thereby improving the efficiency of network transactions. Furthermore, we empirically test our theoretical predictions with the transactional data of second-hand motors from eBay site. This study constructed structure equations that contain the transaction price equation, and trade probability equation and the auction mechanism choice equation. The equation also used Conditional Mixed Process model and maximum likelihood estimation to do regression analysis. The research finds that Buy-it-Now auction could significantly enhance the commodity trade probability and improve transaction prices compared to pure auction if reaching in deal. In addition, compared to the estimation results in Probit model and Heckman model, structural equation with Conditional Mixed Process model solve the sample selection bias and endogeneity problem in a more efficient way. Moreover, the improvement effect of Buy-it-Now auction on online transaction efficiency is more obvious in CMP model. Empirical results show that Buy-it-Now price in online auction mechanism design significantly improves the network transaction efficiency, whether for improving the resource allocation efficiency or increasing the seller‘s expected revenue. The policy implication is very intuitive. Introducing Buy-it-Now auction into the online transaction platform help to improve the efficiency of online transactions. With the rapid development of e-commerce and online trading, it is necessary to enrich and perfect the pricing mechanism of online transactions in China, especially to introduce the Buy-it-Now auction into online auction mechanism.