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The market for widgets consists of two firms that produce identical products. Co

ID: 1226451 • Letter: T

Question

The market for widgets consists of two firms that produce identical products. Competition in the market is such that each of the firms independently produces a quantity of output, and these quantities are then sold in the market at a price that is determined by the total amount produced by the two firms. Firm 2 is known to have a cost advantage over Firm 1. A recent study found that the (inverse) market demand curve faced by the two firms is: P = 280 – 2(Q1 + Q2) and costs are: C1(Q1) = 3Q1 C2(Q2) = 2Q2. Please identify the price each firm will charge, output each firm will produce, and the profit/loss each firm will make.

Explanation / Answer

P = 280 – 2Q1 – 2Q2

So,

Total revenue of firm 1, TR1 = P x Q1 = 280Q1 – 2Q12 – 2Q1Q2

Total revenue of firm 2, TR2 = P x Q2 = 280Q2 – 2Q1Q2 – 2Q22

MC1 = dTC1 / dQ1 = 3

MC2 = dTC2 / dQ2 = 2

So,

Marginal revenue of firm 1, MR1 = dTR1 / dQ1 = 280 - 4Q1 - 2Q2

Equating with MC1:

280 - 4Q1 - 2Q2 = 3

4Q1 + 2Q2 = 277......(1) [Reaction function, firm 1]

Marginal revenue of firm 2, MR2 = dTR2 / dQ2 = 280 – 2Q1 – 4Q2

MC2 = 2

Equating MR2 = MC2,

280 – 2Q1 – 4Q2 = 2

Or,

2Q1 + 4Q2 = 278.......(2) [Reaction function, firm 2]

Equilibrium is obtained by solving (1) & (2).

4Q1 + 2Q2 = 277......(1)

(2) x 2:

4Q1 + 8Q2 = 556 .....(3)

(3) - (1): 6Q2 = 279

Q2 = 46.5

Q1 = (278 – 4Q2) / 2 = [278 – (4 x 46.5)] / 2 = (278 – 186) / 2 = 92 / 2 = 46

Q = Q1 + Q2 = 46 + 46.5 = 92.5

P = 280 - 2Q = 280 - (2 x 92.5) = 280 – 185 = 95

Profit of firm 1 = TR1 – TC1 = (P x Q1) – 3Q1 = Q1 x (P – 3) = 46 x (95 – 3)

= 46 x 92 = 4,232

Profit of firm 2 = TR2 – TC2 = (P x Q2) – 2Q2 = Q2 x (P – 2) = 46.5 x (95 – 2)

= 46.5 x 93 = 4,324.5