Price elasticity of demand is defined as how demand changes as a result of a change in price. It can be said that if a reduction in price leads to an increase in demand then demand is relatively elastic. Elasticity is usually negative. There is an alternative scenario where demand will increase as price does so too. This happens only in the case of Giffen goods, where elasticity is positive. The formula for price elasticity of demand is: Percentage Change in Quantity Demanded One determinant of price elasticity is the number and closeness of substitutes there are available for a good. The closer the goods are, th