The UK oil industry consists of 3 main retail ownership models. The 3 models are oil companies, independent retailers and supermarkets. The concentration rate in the retail gasoline market has seen some changes over the past ten years. Since 2004, supermarket market share has increased by 10%, from 29% to 39%. During the same period, the market shares of oil companies and independent dealers fell by 8%, from 37% to 29%, and 1.6%, from 34% to 32.4%, respectively. (UK Petrol and Diesel Industry, 2013: 44-45). Please refer to Appendix A for graphs. If we look at the market by ownership types, it looks like an oligopoly since 3 ownership types dominate the industry. However, if we break it down by company, the statistics reflect the opposite. Using the Herfindahl–Hirschman index, where each company's market share is squared and added, we can determine the concentration of the UK petrol retail market. (Modern Analyst, 2013) Please refer to Appendix B for the table and values. HHI = 16² + 15² + 14.1² + 10.4² + 9.7² + 9.4² + 6.1² + 5.4² + 4² + 2.4² + 2.4² + 1.2² + 1.2² + 1 .1² + 0.7² + 0.5² + 0.2² + 0.1² + 0.1² + 0.1²= 1,069.21 The HHI value being between 1,000 and 1,800. The retail market of Petrol in the UK is considered moderately concentrated, indicating that it is more of a monopolistic competition than an oligopoly. Although independent dealers account for 32.4% of the petrol market share, they own 59.9% of the UK's petrol stations. Oil companies and supermarkets own 25.5% and 14.6% of UK fleets respectively. (UK Petrol and Diesel Industry, 2013: 45). Please refer to Appendix C for graphs. Even though supermarkets have the fewest forecourts, they have the highest market ever. This shows that the retail gasoline market is experiencing a reduction in non-competitive behavior, as larger retailers are not dramatically reducing gasoline prices. There is substantial evidence demonstrating that corporate behavior falls within the framework of a non-collusive oligopoly: the kinked demand curve theory, in which prices remain stable with little apparent price competition. While the market shares of ownership types suggest that the UK oil market is moving more towards monopolistic competition than oligopoly, the way in which companies behave indicates otherwise. Even though monopolistic firms and oligopolies engage in priceless completion activities, the firms are interdependent and there are considerable barriers to entry. In this case, the UK petrol retail market reflects a competitive oligopoly as retailers compete with each other..