{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

m256hw03soln

# m256hw03soln - 2012 Steven Tschantz Math 256 Assignment 3...

This preview shows pages 1–3. Sign up to view the full content.

© 2012 - Steven Tschantz Math 256 - Assignment 3 Duopoly Enter your name here 1/24/12 Problem Two firms sell similar products in competition, setting prices to attract consumers. Consumers don't view these products as exactly equivalent, but if the price of one product goes up, some who would buy that product instead switch to the other. The firms do not cooperate in setting prices, they set price to do the best for themselves. What prices do they set? What would happen to prices if the firms merge? Model Economists describe this as Bertrand competition between firms selling differentiated products. The products are (partial) substitutes. The assumption is that firms set prices independently, without cooperation or coordination, each in order to maximize their own profits. The competition can be thought of as a game. Each player makes a choice of strategy (price) and the result for each player is the payoff they get (the profit they make). Players make their choices simultaneously without communicating or negotiating. Each player will choose a strategy to maximize its payoff knowing that the other player will choose its strategy to maximize its payoff. If player A were to choose strategy a 1 say, and player B knows this, then player B might want strategy b 2 to maximize its payoff. But if player A knows B will choose strategy b 2 , then A may want a 3 as its strategy. Then B might prefer strategy b 4 , and back and forth endlessly. What we want is a strategy a for A for which the best B can do is a strategy b and such that the best A can do in response to b is the original a . A pair of strategies H a , b L satisfying this condition is called a Nash equilibrium of the game and is thought of as a solution for the game. What we assume then is that each firm takes the competition's price as a given, looks at the demand for its own product as a function of its own price, and sets the price that maximize its own profits. As before, to determine a firm's profit maximizing price we need to know the demand it faces and its costs. The cost of each firm can reasonably be assumed to be a function of the quantity it produces and sells. However, the demand for each firm's product is a function of the prices of both products. Let the firms, and their corresponding products, be denoted by 1 and 2, with prices p 1 and p 2 and quantities q 1 and q 2 . Suppose firms face costs C 1 H q 1 L and C 2 H q 2 L . Assume demands are specified by functions q 1 = q 1 H p 1 , p 2 L and q 2 = q 2 H p 1 , p 2 L . Then the profit for firm 1 is P 1 H p 1 , p 2 L = p 1 q 1 H p 1 , p 2 L - C 1 H q 1 H p 1 , p 2 LL and similarly for the profit of 2, P 2 H p 1 , p 2 L . When firm 1 sets price, it takes p 2 as given. It's maximum profit should be at a critical point of P 1 taken as a function of p 1 . The first order condition on firm 1's maximum profit is then 0 = ¶P 1 p 1 = q 1 H p 1 , p 2 L + H p 1 - mc 1 L q 1 H p 1 , p 2 L p 1 (1) where mc 1 = C 1 ' H q 1 H p 1 , p 2 LL is the marginal cost for product 1. If q 1 doesn't depend on p 2 this reduces to finding the

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
optimal price for a monopolist. At the same time, firm 2 takes
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### What students are saying

• As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

Kiran Temple University Fox School of Business ‘17, Course Hero Intern

• I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

Dana University of Pennsylvania ‘17, Course Hero Intern

• The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

Jill Tulane University ‘16, Course Hero Intern