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Lecture 11. ECON 4100: Industrial Organization. Dynamic games and First and Second Movers (The Stackelberg Model). Oligopoly Models. There are three dominant oligopoly models Cournot Bertrand Stackelberg
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Lecture 11 ECON 4100: Industrial Organization Dynamic games and First and Second Movers (The Stackelberg Model)
Oligopoly Models • There are three dominant oligopoly models • Cournot • Bertrand • Stackelberg • Now we will consider the Stackelberg Model (due to Heinrich von Stackelberg, 1934, about a century after Cournot’s)
Stackelberg • Interpret in terms of Cournot • Firms choose outputs sequentially • leader sets output first, and visibly (IBM, Boeing, the leader is some easily visible firm ) • follower then sets output • The firm moving first has a leadership advantage or first-mover advantage • can anticipate the follower’s actions • can therefore manipulate the follower • For this to work the leader must be able to commit to its choice of output • Strategic commitment has value
Stackelberg Equilibrium: an example Both firms have constant marginal costs of $10, i.e., c = 10 for both firms • Assume that there are two firms with identical products • As in our earlier Cournot example, let demand be: P = 100 - 2Q = 100 - 2(q1 + q2) • Total cost for for each firm is: C(q1) = 10q1; C(q2) = 10q2 • Firm 1 is the market leader and chooses q1 • In doing so it can anticipate firm 2’s actions • So consider firm 2. Demand is: P = (100 - 2q1) - 2q2 • Marginal revenue therefore is: MR2 = (100 - 2q1) - 4q2
Equate marginal revenue with marginal cost This is firm 2’s best response function Stackelberg equilibrium (cont.) Solve this equation for output q2 But firm 1 knows what q2 is going to be MR2 = (100 - 2q1) - 4q2 q2 Firm 1 knows that this is how firm 2 will react to firm 1’s output choice MR = (100 - 2q1) - 4q2 = 10 = c We can calculate that 22.5 is actually the monopoly output. This is an important result. The Stackelberg leader chooses the same output as a monopolist would. But firm 2 is not excluded from the market q*2 = 22.5 - q1/2 So firm 1 can anticipate firm 2’s reaction Demand for firm 1 is: P = (100 - 2q2) - 2q1 22.5 P = (100 - 2q*2) - 2q1 Equate marginal revenue with marginal cost P = (100 - (45 - q1)) - 2q1 S 11.25 => P = 55 - q1 Solve this equation for output q1 R2 Marginal revenue for firm 1 is: q1 MR1 = 55 - 2q1 45 22.5 55 - 2q1 = 10 => q*1 = 22.5 => q*2 = 11.25
Stackelberg equilibrium (cont.) Leadership benefits the leader firm 1 but harms the follower firm 2 Aggregate output is 33.75 Leadership benefits consumers but reduces aggregate profits q2 Firm 1’s best response function is “like” firm 2’s So the equilibrium price is $32.50 45 Firm 1’s profit is (32.50 - 10)22.5 R1 Compare this with the Cournot equilibrium p1 = $506.25 Firm 2’s profit is (32.50 - 10)11.25 p2 = $253.125 22.5 We can check that the Cournot equilibrium is: C 15 S 11.25 qC1 = qC2 = 15 R2 q1 The Cournot price is $40 15 45 22.5 Profit to each firm is $450
Stackelberg and Commitment • It is crucial that the leader can commit to its output choice • without such commitment firm 2 should ignore any stated intent by firm 1 to produce 45 units • the only equilibrium would be the Cournot equilibrium In fact the model is incomplete unless we manage to explain this ability to make a credible commitment It is not easy to commit in a credible manner to producing output
Stackelberg and Commitment • So how to commit? • prior reputation • investment in additional capacity • place the stated output on the market Therefore, commitment could be better understood in terms of committing to the capability of producing output We want to locked-in the cost of capacity (a sunk cost) to show that we mean business. This investment needs to be visible for it to be worthwhile
Stackelberg and timing • Finally, the timing of decisions matters (for some reason, one firm got there first and then has a way to commit through sunk investments in capacity) • There is much more we can learn later in terms of entry-deterrence too
Stackelberg and Efficiency • If unit costs are constant, Stackelberg’s equilibrium will result in a Pareto improvement relative to Cournot’s equilibrium, because the quantity produced increases • However, if the leader is relatively inefficient, then we cannot really say if this equilibrium will be better than the simultaneous choice of output • Passing output production from the efficient follower to the inefficient leader imposes an inefficiency that might not be counteracted by the efficiency increase associated with extra overall output • …and Stackelberg leaders can get very inefficient in real life (due to X-inefficiency for example)
Next: • Monopoly Power and Predatory Conduct • We will learn about: • Entry and exit, predatory conduct, and incumbent/entrant firm models • Dynamic strategic interaction and credible commitment • Limit pricing and public policy