10.1 Monopoly Monopoly-Market with only one seller Monopoly power-The ability of a firm to profitably charge a price higher than marginal cost. Monopsony-Market with only one buyer. Monopsony power-Buyer's ability to affect the price of a good. Marginal revenue-Change in revenue resulting from a 1 unit increase in output.10.1 Monopoly  Monopoly - Market with only one seller  Monopoly power - The ability of a firm to profitably charge a price higher than marginal cost.  Monopsony - Market with only one buyer.  Monopsony power - Buyer’s ability to affect the price of a good.  Marginal revenue - Change in revenue resulting from a 1 unit increase in output