In: Economics
Consider a public good with only two consumers, A and B. The demand function by Customer A is Q = 10 - 0.5P, while the demand function by Customer B is Q = Q = 10 - 0.25P, where Q is quantity demanded and P is price. Construct the market demand curve for the public good. If a company can produce the public good at a constant marginal cost of $30, what is the market equilibrium price and quantity of the public good?
The demand for customer A is Q1 = 10 - 0.5 P
Demand for customer B is Q2 = 10 - 0.25P
The market demand is the sum of individual demand equations of customer A and customer B
Q = Q1 + Q2
Q = 10 - 0.5 P + 10 - 0.25P
Q = 20 - 0.75 P
The market demand equation is Q = 20 - 0.75 P
To construct the market demand curve, we have to make a price & demand table
Price (Y) | Quanity demanded (X) |
0 | 20 |
4 | 17 |
8 | 14 |
12 | 11 |
16 | 8 |
20 | 5 |
24 | 2 |
The firm can produce at a constant marginal cost of $30 , hence its supply curve will be
P = 30Q
Qs = 0.033 P
The market equilibrium occurs when the quantity demanded equals quantity supplied i.e. Qd = Qs
Qd = 20 - 0.75 P & Qs = 0.033 P
Equating both the equation
20 - 0.75 P = 0.033 P
Market equilibrium price P = $ 25.5
Market equilibrium quantity = 20 - 0.75 $ 25.5
Market equilibrium quantity = 0.875 1
Market equilibrium quantity = 1 unit
Market equilibrium price = $ 25.5