Effect of the Merger between Nippon Oil and Kyushu Oil in 2008

This study examines the effect of the merger between Nippon Oil and Kyushu Oil in 2008 on the Japanese gasoline market. This merger was thought to have a significant impact on the market because the former had the top share in the market at that time. In order to focus on the change in Japanese retail gasoline prices, this study adopts the analysis of difference-in-differences. Because there were many Kyushu Oil stations in the Kyushu region while there were few in other regions, this study compares price changes between the Kyushu and neighboring regions. As a result of the analysis, we find that there was little difference in price changes between the two regions after the merger. JEL codes: L44, G34, L11, D22