Friday, March 15, 2019

PRACTICAL APPROACH TO MARKET EQUILIBRIUM AND EFFECT OF TAX



The market supply and demand function are as follows:

Qd =1200-2P

Qs = 4P

On the basis of this information, answer the following:

a) Determine the equilibrium price and quantity

b) What is the effect of tax Rs 50 per unit on production?



Solution:

In the above question, the demand function is :

Qd =1200-2P

Similarly, the supply function is :

Qs = 4P

a) Computation of equilibrium price and quantity

As we know, at equilibrium point the market demand equals market supply.

In other words,

Qd = Qs

Putting the values of Qd and Qs

1200-2P = 4P

6P = 1200

Or, P = Rs.200


Now, putting the value of P in demand function

Qd = 1200 – 2p = 1200 -2 x 200 = 800 unit.


Similarly, putting the value of P in supply function

Qs = 4P = 4 X 200 = 800 unit.


Therefore, the required equilibrium price and quantity is Rs. 200 and 800 units respectively.

b) Computation of Effect due to tax of Rs 50 per unit on production:


Since, the effect of tax do not affect the market demand function but affects the market supply function, we need to first compute the new market supply function by considering the effect of tax.

Market Demand Function:

Qd = 1200 – 2P

Market Supply Function:

Qs = 4 (P – 50 )

Or Qs = 4P – 200

Again, at Market Equilibrium Point

Qd = Qs

Putting the values of Qd and Qs

1200-2P = 4P – 200

Or, 6P = 1400

Or, P = Rs. 233.33

Now, Putting the value of P in demand function

Qd = 1200 – 2p = 1200 -2 x 233.33 = 733.33 = 733 unit


Similarly, putting the value of P in supply function

Qs = 4P – 200 = 4 X 233.33 – 200 = 733.33 = 733 unit



Therefore, the new equilibrium price and quantity is Rs. 200 and 800 units respectively.




Effect before tax
Effect after tax
Price
Rs. 200
Rs. 233.33
Quantity
800 Unit
733 unit

The effect of tax is that, it increases the price and decreases the quantity.



Tutorial Note :
                   
If there would be subsidy in the question then, add the government subsidy in the supply function and solve the problem accordingly. Subsidy decreases price and increases quantity.