Asymmetric behaviour and the 9-ending pricing of retail gasoline

Using daily unleaded gasoline data for almost the totality of Western Australian retail outlets over twentyyears, we find that retail prices are most rigid when they are 9-ending as opposed to other price endings.Upward rigidity from a 9-ending retail price is found to be greater than downward rigidity in terms of a lowernumber of price movements. Irrespective of whether or not a 9-ending price is being charged, an upwardgasoline price movement is likely, in absolute terms, to lead to a larger size of price change than a downwardmovement. In sharp contrast, we find that wholesale gasoline prices are not characterised in such ways andthat irrespective of whether or not taxes are included, there is uniformity across the frequency distributionof price endings. The presence of 9-ending pricing affects the nonlinear response of retail gasoline prices towholesale price movements.