We analyze price dispersion using panel data from a large price comparison site. We use past pricing behavior to instrument for potential endogeneity of firms to select into certain product markets. Our main result is that greater price adjustment costs result in greater price dispersion even in e-commerce markets where price adjustment cost are thought to be negligible. Although the impact of price adjustment costs on price dispersion became weaker over time, the causal effect of price adjustment costs on price dispersion is still present at the end of our observation period. Our results are robust to many alternative empirical specifications. We also control for a range of alternative explanations of price dispersion, such as search cost, service differentiation, obfuscation, vertical restraints, and market structure.

我们使用来自大型价格比较网站的面板数据分析价格分散。我们使用过去的定价行为来衡量公司潜在的内生性，以选择进入某些产品市场。我们的主要结果是，即使在价格调整成本被认为可以忽略不计的电子商务市场中，更大的价格调整成本也会导致更大的价格分散。虽然价格调整成本对价格分散的影响随着时间的推移逐渐减弱，但在我们观察期末，价格调整成本对价格分散的因果效应仍然存在。我们的结果对许多替代的经验规范都是稳健的。我们还控制了一系列价格分散的替代解释，例如搜索成本、服务差异化、混淆、纵向约束和市场结构。