In: Economics
|ES|= 3 and |EW|= 2
Lerner Index is used as tool to measure Market Power of any firm. It gives the markup of a firm over its Marginal Cost. The same can be formulized as:
L = P – MC / P Or L = 1 / | E| |
L = Lerner Index
P = Firm’s Price
MC = Marginal Cost
| E | = Elasticity of demand
Extremes of Lerner Index:
· Perfect Competition – A perfectly competitive firm quotes that price which is equal to its marginal cost. Thus here; L = 0.
· Monopoly - Since a monopolistic firm faces a downward sloping demand curve, which means it charges a price which is higher than the marginal cost. Thus, L> 0.
So, Lerner Index always lies between the values of 0 and 1. If a firm’s “L” tends more towards 0, it generally behaves like a perfectly competitive firm. If a firm’s “L” tends more towards 1, it has greater market power and operates like a monopoly.
Considering the above theory we can solve the below answers:
Given MC = $ 4
|ES| = 3
|EW| = 2
Let Ps = Price charged to students & Pw = Price charged to Working Adults
Let Ls = Lerner Index of students & Lw = Lerner Index of Working Adults
a) Lerner Index of Market Power in student market
Ls = 1 / |ES| = 1 / 3 = 0.33
b) Lerner index of market power in working adult market
Lw = 1 / |EW| = 1 / 2 = 0.5
c) Monopoly price charged to students
Ls = Ps– MC / Ps
Since Lerner index in student market is 0.33:
0.33 = Ps – 4 / Pw
0.33*Ps = Ps – 4
4 = Ps -0.33Ps
Solving for Ps, we get 4 = 0.67Ps
Thus Ps = 4/0.67 = $ 5.97 which is the monopoly price charged to students.
d) Monopoly price charged to working adults
Lw = Pw – MC / Pw
0.5 = Pw – 4 / Pw
0.5Pw = Pw -4
4 = Pw – 0.5Pw
Solving for Pw, we get 4 = 0.5Pw
Pw = 4/0.5 = $ 8 , which is significantly higher than the marginal cost.