Online Price Dispersion: An International Comparison

Abstract

Online price dispersion has remained a puzzle for many years. In this article, we test the effects of a range of factors identified in the literature including vendor strategy, market structure, vendor heterogeneity and the time dimension. We use a dataset collected from the Amazon.com, Amazon.uk and the Amazon.fr marketplaces for books, CDs and DVDs from March to November 2006. First, using posted prices, we show that vendors make few modifications to their prices over time (once every 20 to 30 days), and those variations that they do make are relatively small (on average 15 cents). Secondly, we compare posted prices to transaction prices and we show that transaction prices do not necessarily correspond to the lowest posted price but rather centered around the median prices. Thirdly, we show that online price dispersion increases with the number of sellers mainly because new sellers price their product significantly lower that the current median price. Fourth, we show that there is a significant reputation premium of about 10 to 15%. A well established seller can charge a price 10 to 20% higher than the average seller. Our estimation results support the idea that price dispersion is sensitive to the maturity of the market. Consistent with our finding that price dispersion increases with the number of sellers, less mature markets, such as France with fewer sellers, exhibit lower price dispersion. Similarly, we find that large sellers account for a greater proportion of transactions in France than in the U.S. Lastly, we find that public policy can affect price dispersion: a French law limiting discounting on new books results in lower price dispersion in the French book market relative to book markets in the US and UK and relative to the French market for other goods.