One study found that the price elasticity of demand for soda is -0.78, while the price elasticity of demand for Coca-Cola is -1.22. Coca-Cola is a type of soda, so why isn't its price elasticity the same as the price elasticity for soda as a product? Source: Kelly D. Brownell and Thomas R. Frieden, "Ounces of Prevention- The Public Policy Case for Taxes on Sugared Beverages," New England Journal of Medicine, April 30, 2009, pp. 1805-1808.