Title: Price changes in the gasoline market: Are Midwestern gasoline prices downward sticky?

This report examines a recurring question about gasoline markets: why, especially in times of high price volatility, do retail gasoline prices seem to rise quickly but fall back more slowly? Do gasoline prices actually rise faster than they fall, or does this just appear to be the case because people tend to pay more attention to prices when they`re rising? This question is more complex than it might appear to be initially, and it has been addressed by numerous analysts in government, academia and industry. The question is very important, because perceived problems with retail gasoline pricing have been used in arguments for government regulation of prices. The phenomenon of prices at different market levels tending to move differently relative to each other depending on direction is known as price asymmetry. This report summarizes the previous work on gasoline price asymmetry and provides a method for testing for asymmetry in a wide variety of situations. The major finding of this paper is that there is some amount of asymmetry and pattern asymmetry, especially at the retail level, in the Midwestern states that are the focus of the analysis. Nevertheless, both the amount asymmetry and pattern asymmetry are relatively small. In addition, much of the pattern asymmetry detected in this and previous studies could be a statistical artifact caused by the time lags between price changes at different points in the gasoline distribution system. In other words, retail gasoline prices do sometimes rise faster than they fall, but this is largely a lagged market response to an upward shock in the underlying wholesale gasoline or crude oil prices, followed by a return toward the previous baseline. After consistent time lags are factored out, most apparent asymmetry disappears.