Asymmetric Price Adjustment and Consumer Search: An Examination of the Retail Gasoline Market

It has been documented that retail gasoline prices respond more quickly to increases in wholesale price than to decreases. However, there is very little theoretical or empirical evidence identifying the market characteristics responsible for this behavior. This paper presents a new theoretical model of asymmetric adjustment that empirically matches observed retail gasoline price behavior better than previously suggested explanations. I develop a “reference price” consumer search model that assumes consumers’ expectations of prices are based on prices observed during previous purchases. The model predicts that consumers search less when prices are falling. This reduced search results in higher profit margins and a slower price response to cost changes than when margins are low and prices are increasing. Following the predictions of the theory, I use a panel of gas station prices to estimate the response pattern of prices to a change in costs. Unlike previous empirical studies I focus on how profit margins (in addition to the direction of the cost change) affect the speed of price response. Estimates are consistent with the predictions of the reference price search model, and appear to contradict previously suggested explanations of asymmetric adjustment. ∗E-mail: [email protected]. I would particularly like to thank Severin Borenstein, as well as Richard Gilbert, Stephen Holland, Aviv Nevo, Carl Shapiro, Celeste Saravia, Frank Wolak, Catherine Wolfram and everyone at the University of California Energy Institute for advice and financial support. I would also like to thank Charles Langley (UCAN) for collecting and providing the data used in this paper.