Problems Using Point Elasticity

- We may need to compute price elasticity over portion of demand curve instead of at a single point.

- The price and quantity used as base will alter price elasticity of demand.

Point Elasticity of Demand: An Example

-Assume that

• Price rises from 8$ to $10 quantity demanded falls from 6 to 4
• The percent change in price equals: $2/$8 = 25% or $2/$10 = 20%
• The percent change in quantity equals: -2/6 = -33.33% or -2/4 = -50%

 Elasticity equals:

 -33.33/.25 = -1.33 or -.50/.20 = -2.54

-Which one is correct out of these?