电子商务、搜寻成本与消费价格变化

E-Commerce,Searching Cost and Consumer Price Change:Evidence from the Micro Retailing Market

电子商务交易平台通过有效提高消费者搜寻次数、降低市场搜寻成本,对零售市场的价格产生了显著影响。基于搜寻理论框架,本文首先构建了一个包含消费者差异性的搜寻与匹配效率理论框架,并且基于1999—2012年的月度微观价格监控数据,以淘宝网的B2C交易平台作为典型案例研究,通过多重差分的方法检验了理论假说。我们发现:首先,消费者通过电子商务交易平台搜寻商品效率对商品市场均衡价格的影响具有产品差异性,对价格低于一定水平的商品,消费者的搜寻效率提高会使商品均衡价格上升;而对价格高于一定水平的商品,消费者的搜寻效率提高会使商品均衡价格下降。其次,消费者运用电子商务平台的边际搜寻成本对商品均衡价格的影响具有消费市场的差异性。实证方面,本文分别运用倍差法和三重差分方法检验了上述两个理论假说中的电子商务平台对商品均衡价格影响的产品和城市差异性,并运用城市差异性指标刻画了搜寻成本。本文结果在进行若干稳健性检验后仍是稳健的。

The rapid development of e-commerce has changed China＇s economy dramatically, especially the domestic consumer price of various kinds of goods. This study theoretically and empirically tests the impact of e-commerce on China＇s domestic micro retailing goods. By applying the micro retailing price of various kinds of consumer goods, the paper reveals the direct effect of e-commerce on a micro level rather than on a macroeconomic level. The literature shows that e-commerce has had a significant impact on specific industries （Lee and Clark, 1996; Lee, 1998; Brynjolfsson and Smith, 1999; Haynes and Thompson, 2008）. Moreover, consumer demand is influenced by income distribution, the household registration system, and external shock （Chen, 2012; Dai and Mao, 2015）. However, this research lacks more theoretical support and empirical evidence on the micro level. From the theoretical perspective, searching theory provides one possible explanation for the impact of e-commerce on consumer price in the micro retailing market. The theory argues that the clustering of homogeneous goods on e-commerce platforms is effective in enhancing market competition and decreasing the retailing price of goods （Heil and Prieger, 2009; Tang et al. , 2010; Waldeck, 2002）. We introduce searching time and cost into the e-commerce searching model, and use micro-level data on retailing price and the difference-in-differences method to test the aforementioned impact empirically. In terms of the representative consumer＇s searching time, this paper formulates the theoretical hypothesis that the number of searches （ or efficiency） has different effects on the retail price of different commodities. We also reveal the impact of the representative consumer＇s marginal e-commerce searching cost on the retailing price of different categories. Based on the theoretical model, we apply the micro-level retailing prices from January 1999 to December 2012 collected from the Consumer Price Institution of China to test the preceding hypothesis. To avoid the endogeneity problem between retailing price and e- commerce, we apply the empirical methods of difference-in-differences to test the impact of the founding of Taobao, the largest e-commerce platform in China, on the retailing price of necessities, middle-and high-level daily-use goods, and electronic equipment. To control the macroeconomic differences between different cities, such as transport costs, fiscal expenditure, and economic developments, we apply various control variables collected from China＇s urban statistical yearbook. The results of our paper are as follows. First, searching times by consumers through e-commerce websites have different effects on goods of different categories. For necessities with prices lower than the threshold level, the greater the ecommerce searching time, the higher the retailing prices. Meanwhile, for goods with prices higher than the threshold level, such as middle-and high-level daily-use goods and electronic equipment, the greater the e-commerce searching time, the lower the retailing prices. Second, the marginal cost of searching through e-commerce is negatively related to the retailing price of necessities, middle-and high-level daily-use goods, and electronic equipment. The results of our paper indicate that searching through e-commerce can smooth the retailing price in China through two channels ： greater searching time and lower marginal searching cost. Therefore, one possible strategy for stabilizing the price is to develop e-commerce in China. However, considering that the marginal cost of searching is closely related to the internet infrastructure of different cities, we strongly suggest that city governments pay more attention to developing and upgrading a given region＇s internet infrastructure. Furthermore, we suggest that the Chinese government make more efforts to narrow the gap of internet infrastructure between different cities and lead the balanced development of e-commerce.