Elasticity - Own Price Elasticity of Demand

To the left is the arc elasticity version of the own price elasticity of demand. Let's recompute our last example using the arc elasticity formula. As before, price drops from 12 to 8 and quantity demanded rises from 1 to 2, giving the results shown to the right. A quick check will confirm that the formula gives the same result if price falls from 12 to 8 or increases from 8 to 12. This is a nice characteristic of the arc elasticity formula. The somewhat cumbersome nature of the formula is its main drawback.