3) Monopoly Pure monopoly is one in which there is only one producer in the sector. In reality it rarely exists – some form of substitute is always available. Monopoly exists, therefore, where one company dominates the market. The forms can be studied for examples of monopoly power when the market share exceeds 25%. The summary of characteristics of the firm exercising monopoly power would be: Price – may be considered too high, may be set to destroy competition, possible price discrimination. Efficiency – could be inefficient due to lack of competition or could be higher due to availability of high profits. 4) Oligopoly An oligopoly is a market structure in which a few firms dominate. When a market is shared among a few companies it is said to be highly concentrated. Although only a few firms dominate the market, it is possible that many small firms also operate in the market. Competition among a few companies may be represented by a large number of companies in the industry, but the industry is dominated by a small number of very large manufacturers. Concentration ratio: the percentage of total market sales (share) held by the top 3,4,5 etc. of firms: Has an oligopolistic market structure: The price can be relatively stable in