Stricter environmental standards on gasoline have had impacts on the prices of gasoline including the seasonality of gasoline prices. Using both national data and individual station data, the paper tests for a possible explanation for this increase. Three theories are tested: that gasoline seasonality increases due to higher costs, due to greater market power because of segmented markets, or due to greater asymmetry because of greater inattention on the part of customers. The results suggest that gasoline price seasonality has increased both due to higher costs and greater market power with mixed results on the inattention of consumers.(JEL Q41, Q53, Q58)
