The document discusses monopoly in the short run. It defines monopoly as a market with a single seller and no substitutes for the good. It notes key characteristics of monopoly include: one firm controls the industry; goods have no substitutes; there is no freedom of entry or exit; and the firm determines price. The document discusses how a monopoly faces a downward sloping demand curve and can influence price or quantity but not both. It provides examples of how to calculate total revenue, average revenue and marginal revenue from demand. It also discusses the relationships between demand, marginal revenue, and average revenue curves. Equilibrium for the monopoly occurs where marginal revenue equals marginal cost, and it can result in super normal profit, normal profit, losses or