In: Economics
1. Consider a differentiated Bertrand market with three firms, whose demand curves are:
Q1 = 300-10P1+3P2 +2P3
Q2 = 300-8P2 +2P1 + P3
Q3= 50-3P3+P1+P2.
Firms 1 and 2 both have marginal costs of 10 and Firm 3 has a marginal cost of 15.
a. Calculate the equilibrium prices and quantities.
b. Calculate the market shares.
c. By specific reference to the HMGLs, would the two lead federal agencies be likely to regard a merger between Firm 2 and Firm 3 as one that would likely raise serious competitive concerns?
d. Calculate the UPPIs for the merging parties. Assume that Firm 3’s marginal cost falls to 10 as a result of the merger.
1.
Q1=300-10P1+3P2+2P3
Q2=300-8P2+2P1+P3
Q3= 50-3P3+P1+P2
MC1=10
MC2=10
MC3=15
a)
Profit of firm 1= Pr1= P1 x Q1 - Q1 x MC1
Pr1= P1(300-10P1+3P2+2P3)-(300-10P1+3P2+2P3)10
Pr1= 300P1-10P12+3P1P2+2P1P3-3000+100P1-30P2-20P3
Differentiate with respect to P1
dPr1/dP1= 300-20P1+3P2+2P3+100=0
(400+3P2+2P3)/20= P1 reaction curve of firm 1(BRS 1)
Profit of firm 2= Pr2= P2 x Q2 - Q2 x MC2
Pr2= P2(300-8P2+2P1+P3)-(300-8P2+2P1+P3)10
Pr2= 300P2-8P22+2P1P2+P3P2-3000+80P2-20P1-10P3
Differentiate with respect to P2
dPr2/dP2= 300-16P2+2P1+P3+80=0
P2= (380+2P1+P3)/16 reaction curve of firm 2(BRS 2)
Profit of firm 3= Pr3= P3 x Q3 - Q3 x MC3
Pr3= P3( 50-3P3+P1+P2)-( 50-3P3+P1+P2)15
Pr3= 50P3-3P32+P1P3+P2P3-750+45P3-15P1-15P2
Differentiate with respect to P3
dPr3/dP3= 50-6P3+P1+P2+45=0
P3= (95+P1+P2)/6 reaction curve of firm 3 (BRS 3)
Solve BRS 3 by putting value of P2 from BRS of firm 2
P3= (95+P1+P2)/6
6P3= [95+P1+(380+2P1+P3)/16)]
16 X 6P3= 1520+16P1+380+2P1+P3
95P3= 1900+18P1
P3*= (1900+18P1)/95
Put P3* into BRS of firm 2
P2=(380+2P1+P3)/16
16P2=380+2P1+(1900+18P1)/95
95x16P2= 38000+208P1
P2*= (38000+208P1)/1520
Use P1* and P2* in BRS 1
P1= (400+3P2+2P3)/20
20P1= 400+3[(38000+208P1)/1520]+2[(1900+18P1)/95 ]
144400x20P1= 57760000+10830000+59280P1+5776000+54720P1
144400x20P1= 74366000+114000P1
2774000P1= 74366000
P1*= 26.80
Use this in P2* and P3*
P2*= (38000+208P1)/1520= (38000+208x26.80)/1520= 28.66
P3*= (1900+18P1)/95 =(1900+18x26.80)/95 = 25.07
Use P1*, P2* and P3* in quantities:
Q1=300-10P1+3P2+2P3= 168
Q2=300-8P2+2P1+P3= 149
Q3= 50-3P3+P1+P2= 30
b) Market share= Quantity/Total market quantity
Total market quantity= 168+149+30= 347
Market share of firm 1= 168/347= 0.48
Market share of firm 2= 149/347= 0.43
Market share of firm 3= 0.09