what is cross elasticity of demand 
the cross elasticity of demand is an economic concept that measures the responsiveness in the quantity demanded of one good when the price for another good changes it s also referred to as cross price elasticity of demand this measurement is calculated by taking the percentage change in the quantity demanded of one good and dividing it by the percentage change in the price of the other good cross elasticity of demand formula e x y percentage change in quantity of x percentage change in price of y e x y q x q x p y p y e x y q x q x p y p y e x y q x p y p y q x where q x quantity of good x p y price of good y change begin aligned e xy frac text percentage change in quantity of x text percentage change in price of y phantom e xy frac frac displaystyle delta q x displaystyle q x frac displaystyle delta p y displaystyle p y phantom e xy frac delta q x q x times frac p y delta p y phantom e xy frac delta q x delta p y times frac p y q x textbf where q x text quantity of good x p y text price of good y delta text change end aligned exy percentage change in price of ypercentage change in quantity of x exy py py qx qx exy qx qx py py exy py qx qx py where qx quantity of good xpy price of good y change 