If consumers' incomes increase at the same time there is a decrease in the cost to produce granite counter tops, which of the following is true?

Question

Quizplus · Accepted Answer

An increase in consumers' incomes will shift the demand curve to the right, causing an increase in both equilibrium price and quantity if supply is unchanged. However, the decrease in the cost to produce granite counter tops will shift the supply curve to the right, causing a decrease in equilibrium price and an increase in equilibrium quantity. Since both the demand and supply curves are shifting to the right, it is certain that the equilibrium quantity will increase.

If Consumers' Incomes Increase at the Same Time There Is