Pure monopoly exists when a single firm is the sole producer of a product for which there are no close substitutes. Examples are public utilities and professional sports leagues, Characteristics 1. A single seller: the firm and industry are synonymous.2. Unique product: no close substitutes for the firm s product. 3.The firm is the price maker: the firm has considerable control over the price because it can control the quantity supplied. 4. Entry or exit is blocked. Barriers to Entry Economies of scale is the major barrier.nique product: no close substitutes for the firm s product. 3. The firm is the price maker: the firm has considerable control over the price because it can control the quantity supplied. 4. Entry or exit is blocked. Barriers to Entry Economies of scale is the major barrier.