Intuition - Why does elasticity vary along a curve?
Source: p 96, *Principles of Microeconomics*, 7 Ed, 2014, by N Gregory Mankiw>Even though the slope of a linear demand curve is constant, the elasticity is not.This is true because the slope is the ratio of ***changes*** in the two variables, whereasthe elasticity is the ratio of ***percentage changes*** in the two variables.>[[Source:]](https://www.boundless.com/economics/textbooks/boundless-economics-textbook/elasticity-and-its-implications-6/price-elasticity-of-demand-54/interpretations-of-price-elasticity-of-demand-210-12301/) Elasticity along a straight line demand curve varies from zero at the quantity axis to infinity at the price axis. ... At the midpoint ... elasticity is equal to one, or unit elastic.Please explain the above intuitively? I ask NOT for a formal proof.
Elasticitity is the percent change in quantity demanded divided by a percent change in price. Consider a demand curve q= 10-p. when p=8 q=2 if p falls to 7 we have a 12.5 percent drop in price and q rises 50% to 3. This is very elastic. when p=2, q = 8. dropping price to 1 is a 50% decrease in price with quantity increasing by only 12.5%. when -Change in Q/ Change in P = P/Q. we will have unit elastic demand
