A numerical tool calculates percentage change between two points, using the average value as the base. In the realm of applied economics, this calculation is frequently employed to determine elasticity a measure of responsiveness of one economic variable to a change in another, such as the change in quantity demanded in response to a change in price. For example, if the price of a good increases from $10 to $12 and the quantity demanded decreases from 20 units to 15 units, the percentage change in price would be calculated using the average price (($10 + $12)/2 = $11) as the base. Similarly, the percentage change in quantity demanded would use the average quantity ((20 + 15)/2 = 17.5) as the base. This provides a more accurate elasticity measurement compared to using either the initial or final value as the base, as it avoids different elasticity values depending on the direction of the change.
Utilizing this approach provides a more reliable and consistent measure of elasticity compared to other methods. This consistency is particularly beneficial for economic analysis and policy decisions. By mitigating the ambiguity caused by differing base values, the resultant elasticity estimates are less prone to distortion, promoting more informed decision-making. Historically, this approach gained prominence as economists sought improved methods for evaluating responsiveness and the effects of policy interventions on markets.
