5) Comparison of the Four Structures: Compare the four industry structures based on quantity, price, profits, and price.  (See Comparing Oligopoly Models.)

1. Perloff Chapter 14, Exercise 3.13 3.13 A duopoly faces an inverse market demand function of p = 120 - Q. Firm 1 has a constant marginal cost of 20. Firm 2's constant marginal cost is 40. Calculate the output of each firm, market output, and price in (a) a collusive equilibrium or (b) a Nash-Cournot equilibrium. (Hint: See Solved Problem 14.10.) M

1. which compete in quantities (Cournot -Nash equilibrium = C) 2. which compete in quantities with the first firm (the Leader) choosing the output first (Stackelberg competition = S). 3. which collude and choose quantities in order to maximize the joint profits (behave like two plants of a multiplant monopoly = M).

Suppose that a small town has seven burger shops whose respective shares of the local hamburger market are (as percentages of all hamburgers sold): 26 percent, 24 percent, 20 percent, 12 percent, 9 percent, 6 percent, and 3 percent. Instructions: Enter your answers as a whole number. a. What is the four-firm concentration ratio of the hamburger industry in this town? Book percent Print b. What is the Herfindahl index for the hamburger industry in this town? erences c. If the top three sellers combine to form a single firm, what would happen to the four-firm concentration ratio and to the Herfindahl index? Four-firm concentration ratio = percent Herfindahl index =

11. Suppose there is a duopoly of two identical firms, A and B, facing a market inverse demand of P = 140 – 0.5Q, and cost functions of CA = 20QA and Cg = 20QB respectively. a. Find the Cournot-Nash equilibrium and profit for each firm. b. Suppose that A acts as the leader in a Stackelberg model and B responds. What are the respective quantities and profits of each firm now? Is it advantageous to move first? c. If the firms were able to collude, how much additional profit could they earn if they switch from simple single pricing to perfect price discrimination? d. Graph and label equilibria on the inverse demand.

5. Two duopolistic oil producers are faced with the total demand function of P = 180– Q and the following cost functions: MC1 = 30 + Q1 MC2 = 20 + 2Q2 a. Determine the optimal levels of output, using the Cournot solution. b. What are the optimal outputs, if the two firms form a cartel

Suppose there are two distinct industries - (1) the fast-food industry and (2) the sporting goods industry. Classify each industry into one of the following market structures. (Minimum word requirement: 100 words) Perfect competition Monopoly Monopolistic competition Oligopoly

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