要旨：Owing to a lack of statistics about gasoline prices at the gasoline stand (GS) level in Japan, there are hardly any studies attempting to identify the factors that influence the retail gasoline prices of each GS. We believe that this is the first attempt to tackle this problem. Using the fairly large spatiotemporal dataset of gasoline prices from 2008 to 2012, we estimate an empirical model of spatial competition among retail GSs. The theory of spatial competition suggests that retail gasoline price is affected by cost, demand, and spatial competition; therefore, these three factors are considered in our empirical analyses. For the first two factors, we introduce various types of spatially fine GIS data, including land prices (cost), population density (demand), etc., and their impacts are statistically verified. The spatial competition factor is considered by employing the latest spatial econometrics/social interaction models, in which spatial price completion can be modeled fairly directly.