Suppose that the four firms are colluding by acting like a monopolist, with each firm producing one-fourth of the market output. If one of the firms cheats on the cartel agreement and produces an additional unit of output, the profits of each of the compliant firms go from:

Complete Question

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the correct answer is (b) decrease from $16 to $14

Explanation:

In order for profit to be maximized by a monopolist quantity produce will be MR = MC  

from above graph MR = MC when Quantity = 8. As they are all producing equal portion of market output Hence Each firm will produce Q = 8/4 = 2 units.

When Market quantity = 8 then price they are getting = 12 per unit (From demand curve)

As there is no fixed cost and MC is constant => Total variable cost = MC*Q = 4Q

=> Total cost(TC) = Total fixed cost + total Variable cost = 0 + 4Q = 4Q

Total revenue = Price * quantity = PQ = 12Q

Hence Profit = 12Q - 4Q = 8Q and as Q = quantity per firm = 2

=> Profit they are earning = 8*2 = 16.

Now Suppose one firm cheats and hence now total quantity produces and sold = 2*3 + 3 + 9.

When Market quantity = 9 then price they are getting = 11 per unit (From demand curve).

Now, Profit = TR - TC = 11Q - 4Q = 7Q and Q remains same for those firms who didn't cheat.

So, Now profit = 7Q = 7*2 = 14.

Thus, If one of the firms cheats on the cartel agreement and produces an additional unit of output, the profits of each of the non cheating firms will decrease from $16 to $14.