In: Economics
Monopoly pricing: Consider a simple linear demand function that intersects the quantity 0 point at $110 and the $0 axis at 1,200 units. The marginal cost is linear and starts at $10 at 0 quantity and reaches $110 at 500 units.
It is probably easiest to use algebraic representations for the curves, rather than trying to do this graphically. Show your work.
(1)
Elasticity of demand is the ratio of percentage change in quantity demanded to the percentage change in price. For a linear demand function of the form Q = a - bP,
Elasticity = (dQ/dP) x (P/Q) = -b x (P/Q)
Since b is a constant (slope of demand line) but P and Q change along the demand curve. Therefore elasticity is not constant.
(2)
(a) Linear demand equation: P = a - bQ
When Q = 0, P = 110
110 = a - 0
a = 110
When P = 0, Q = 1,200
0 = a - 1,200b
0 = 110 - 1,200b
1,200b = 110
b = 0.0917
Demand equation: P = 110 - 0.0917Q
(b) Equation of MC function: MC = c + dQ
When Q = 0, MC = c = 10
When Q = 500, MC = 110
110 = 10 + 500d
500d = 100
d = 0.2
MC equation: MC = 10 + 0.2Q
(c) In competitive equilibrium, P = MC.
110 - 0.0917Q = 10 + 0.2Q
0.2917Q = 100
Q = 343
P = 10 + (0.2 x 343) = 10 + 68.6 = 78.6
(3)
Consumer surplus ($) = Area between demand curve and price = (1/2) x (110 - 78.6) x 343 = 171.5 x 31.4 = 5385.1
(4)
Producer surplus ($) = Area between MC curve and price = (1/2) x (78.6 - 10) x 343 = 171.5 x 68.6 = 11764.9
NOTE: As per Answering Policy, 1st 4 parts are answered.