Few issues generate more attention and anxiety among American consumers than the price of gasoline. The most current upsurge in prices is no exception. According to data from the Energy Information Administration (EIA), the average retail price of regular unleaded gasoline in the United States has increased almost every week this year since January 29th and reached an all-time high of $3.21 the week of May 21st. Over this time period, the price has increase $1.05 per gallon and added about $23 billion to consumers' total gasoline bill, or about $167 for each passenger car in the United States. Given the importance of gasoline for the nation's economy, it is essential to understand the market for gasoline and the factors that influence gasoline prices. In this context, this testimony addresses the following questions: (1) what key factors affect the prices of gasoline and (2) what effects have mergers had on market concentration and wholesale gasoline prices?