In: Economics
In the competitive market for soy beans, there are 520 identical farms, each farm having the cost function. c(q) = .5q2 + 3q + 32 where q is the quantity of output in tons produced by each farm. mc(q) = q + 3. The market demand equation is Qd(p) = 4640 – 100p. • Find a firm’s individual supply equation. • What is the equation for the market supply? What is the equilibrium price and quantity in this market? • What is the q for each firm? • What are profits/losses for each firm? • Should each farm in the short-run stay in business? Explain your answer.
A firms individual supply function is the marginal cost function.
The a single firms supply function is,
P = q + 3
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There are 520 firms in the market.
So, Q = 520q, where Q = Market quantity and q = Each Firm's quantity
At equilibrium,
Price = Marginal Cost
P = MC
Thus we have,
P = q + 3
q = P - 3 -----------> Firm's individual Supply function
Now, we know that,
Q = 520*q
Q = 520*(P - 3)
Q = 520P - 1560 ----------> This the equation for market supply.
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At market equilibrium,
Demand = Supply
4640 - 100P = 520P - 1560
620P = 6200
P = 10 ------------------> Equilibrium Price
Setting P = 10 in the demand function,
Q = 4640 - 100P
Q = 4640 - 100*10
Q = 3640 ----------------> Equilibrium quantity
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We know that,
Q = 520q
520q = 3640
q = 7 -------------------> Each firm's quantity.
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The total cost for each firm at q = 7 is,
C = 0.5q2 + 3q + 32
C = 0.5(7)^2 + 3*7 + 32
C = 77.5
Total Revenue = Price*Quantity of each firm
TR = 10*7 = 70
Profit = Total Revenue - Total Cost
Profit = 70 - 77.5 = - 7.5 ---------------> Loss of each firm
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In the presence of 520 firms, each firm incurs a loss of 7.5. Thus some of the firms will exit the market in the short run until firms start earning normal profit.