||4. In one graph show the difference between a monopolist that can charge only one price and a monopolist that can engage in perfect price discrimination. (Make sure you label all relevant prices and quantities as well as the difference in social welfare.) 45. What term is used by economists when an increase in output results in an increase in a firm's long-run average cost curve? a) Economies of scale b) Economic costs c) Diseconomies of scale d) Capacity constraint e) Scarcity 46. The Ushape of the long-run average (total) cost curve is primarily due to … a) indivisible set-up costs. b) economies and diseconomies of scale. c) technological change and learning by doing. d) government discouragement of small firms and extremely large ones e) initially increasing, but eventually diminishing marginal productivity of the variable input. 47. The short run marginal cost curve in the traditional microeconomic model eventually rises because of… a) diminishing marginal returns. b) rising fixed costs. c) diseconomies of scale. d) diminishing marginal revenues. e) increasing marginal productivity of variable inputs. 48. Economies of scale refer to … a) a firm's marginal costs increasing as the quantity of production increases b) a firm's long-run average costs decreasing as the quantity of production increases. c) a firm's total costs decreasing as the quantity of production increases. d) a firm's opportunity costs decreasing as the quantity of production increases. e) a firm's transactions costs decreasing as the quantity of production increases.