8. show the different methods of measuring elasticity of demand? When should which method be used?
Answers
Answer:
Elasticity of demand is known as price-elasticity of demand. Because elasticity
of demand is the degree of change in amount demanded of a commodity in
response to a change in price. Price elasticity of demand can be measured
through three popular methods. These methods are:
1. Percentage method or Arithmetic method
2. Total Expenditure method
3. Graphic method or point method.
1. Percentage method:-
According to this method price elasticity is estimated by dividing the
percentage change in amount demanded by the percentage change in price of
the commodity. Thus given the percentage change of both amount demanded
and price we can derive elasticity of demand. If the percentage charge in
amount demanded is greater that the percentage change in price, the
coefficient thus derived will be greater than one.
If percentage change in amount demanded is less than percentage change in
price, the elasticity is said to be less than one. But if percentage change of both
amount demanded and price is same, elasticity of demand is said to be unit.
2. Total Expenditure method :-
Total expenditure method was formulated by Alfred Marshall. The elasticity of
demand can be measured on the basis of change in total expenditure in
response to a change in price. It is worth noting that unlike percentage
method a precise mathematical coefficient cannot be determined to know the
elasticity of demand.
By the help of total expenditure method we can know whether the price
elasticity is equal to one, greater than one, less than one. In such a method the
initial expenditure before the change in price and the expenditure after the
fall in price are compared. By such comparison, if it is found that the
expenditure remains the same, elasticity of demand is One (ed=I).
If the total expenditure increases the elasticity of demand is greater than one
(ed>l). If the total expenditure diminished with the change in price elasticity
of demand is less than one (ed<I). The total expenditure method is illustrated
3. Graphic method:
Graphic method is otherwise known as point method or Geometric method.
This method was popularized by method. According to this method elasticity
of demand is measured on different points on a straight line demand curve.
The price elasticity of demand at a point on a straight line is equal to the lower
segment of the demand curve divided by upper segment of the demand curve.
Thus at mid point on a straight-line demand curve, elasticity will be equal to
unity; at higher points on the same demand curve, but to the left of the mid-
point, elasticity will be greater than unity, at lower points on the demand
curve, but to the right of the midpoint, elasticity will be less than unity.