The Effect of Ambiguity on Price Dispersion in Duopoly Markets

Price dispersion remains a persistent feature of markets for many consumer goods. Theoretically, tension between competing for informed consumers and exploiting captive consumers yields mixed strategy pricing equilibria. This paper considers the implications on pricing levels and dispersion when there is ambiguity about a firm’s share of the captive consumers. Said ambiguity forces firms to make pricing decisions without specific probabilities attached to consumer buying habits. The model reveals that ambiguity aversion forces relatively small firms to price higher on average while it causes relatively large firms to price more competitively on average. An experiment provides empirical support for this result, while also showing that individual ambiguity attitudes do not matter when in a market without ambiguity. Additionally, ambiguity significantly lowers price dispersion in markets with a high fraction of informed consumers, while also increasing competition between firms. This effect is primarily driven by the firm with a larger share of captive consumers