Consider a competitive market for which the quantities demanded and supplied (per year) at various prices are given as follows:

Price (dollars) Demand (millions) Supply (millions)

60 22 14

80 20 16

100 18 18

120 16 20

a. Calculate the price elasticity of demand when the price is $80 and when the price is $100.

b. Calculate the price elasticity of supply when the price is $80 and when the

price is $100.

c. What are the equilibrium price and quantity ?

d. Suppose the government sets a price ceiling of $80. Will there be a shortage,

and if so, how large will it be ?

Answer and Explanation:

A. Price elasticity of demand

Price(P0) = $80 , Q0 = 20

Price(P1) = $100 , Q1 = 18

Price elasticity of demand =

Price elasticity of demand = 0.47

B. Price elasticity of supply

Price(P0) = $80 , Q0 = 16

Price(P1) = $100 , Q1 = 18

Price elasticity of supply =

Price elasticity of supply = 0.53

C. The point , where Demand and supply is equal called equilibrium price

So , $100 is equilibrium price.

D. if market price is less then equilibrium price , it is effective So, shortage (20-16) 4 units

they have a larger number of potential customers because people anywhere can buy from them. ( d.)