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Assume that firm 1 performs R&D that benefits firm 2. Firm 1\'s marginal benefit

ID: 1248733 • Letter: A

Question

Assume that firm 1 performs R&D that benefits firm 2. Firm 1's marginal benefits and marginal costs from a quantity x of R&D are given by

MB1(x)= 20 - 10x; MC1(x)=5

Firm 2's benefits from firm 1's R&D are given by MB2 (x) = 2 - x

(i) What is firm 1's optimal choice of R&D if it does not take into account the external benefit to firm 2?

(ii) What is the socially optimal amount of R&D?

(iii) Compute the value of a unit subsidy s that would induce firm 1 to choose the optimal amount of R&D.

Explanation / Answer

Assume that firm 1 performs R&D that benefits firm 2. Firm 1's marginal benefits and marginal costs from a quantity x of R&D are given by

MB1(x)= 20 - 10x; MC1(x)=5

Firm 2's benefits from firm 1's R&D are given by MB2 (x) = 2 - x

(i) What is firm 1's optimal choice of R&D if it does not take into account the external benefit to firm 2?
Optimal choice of R&D is where MC= MB

20 - 10x =5
10x= 15
x= 1.5 units


(ii) What is the socially optimal amount of R&D?
With this positive externality of 2-x, the marginal benifit curve will shift towards its right.
For the new curve we have to add the MB of frim 1 and externality due to firm 1, MB= 2-x

MB curve 2= 20 - 10x + 2 - x
                 = 22 - 11x.

Socially optimum level:

MB2= MC
22- 11x= 5
     11x= 17
        x= 17/11
        x = 1.54


(iii) Compute the value of a unit subsidy s that would induce firm 1 to choose the optimal amount of R&D.

Difference in the the quantity 1.54 - 1.5= 0.04 worth subsidy should be given.
Marginal benifit derived from 0.04 quantity is
MB= 20 - 10(0.04)
     = 20 - 0.4
     = $19.6
should be given in order to produce the socially optimum output.