中文摘要：

以Prosper在线个人借贷平台为研究对象，实证考察了第三方电子交易市场中用户的交叉网络外部性、自网络外部性和平台定价策略对双边用户效用和平台利润的影响．结果表明：受市场供小于求、平台运营模式和借贷双方交易行为的影响，新借入者规模对借出者收入、前期借出者总规模对借入者需求均产生了显著的正交叉网络外部性；借入者之间由于竞争存在负自网络外部性，而借出者之间由于协同关系存在正自网络外部性；借贷双方对平台交易费具有显著的负价格弹性，平台利润与借贷双方的交易费分别呈现二次线性关系；在市场供小于求的情况下，平台利润主要受到借出者规模及其费率的影响．

英文摘要：

Based on the data of an online peer-to-peer lending marketplace, Prosper. corn, the users＇ inter and intra-group externalities and platform＇s pricing strategies in the third-party electronic market are empiri- cally investigated. The estimated results show that both the users＇ network effects and platform＇ s profits are influenced by the demand-supply relationships, the operation mode of the platform and the users＇ trading be- havior in the market. There are positive inter-group network externalities between the lenders and borrowers, negative intra-group network externalities among the borrowers and positive intra-group network externalities a- mong the lenders. Borrowers and lenders are both sensitive to the rates of transaction fees set by the platform, and the profit of the platform has quadratic relations with the supply than demand in the marketplace, the platform＇ s profit rates of transaction fees. Because there is less is mainly affected by the size of the lenders and the transaction fee rate of the lenders.