1.5.1 According to the World Health Organization, the number of countries with tax shares represent ing more than 75% of the retail price of the most popular brand of cigarettes increased significantly between 2008 and 2012. If raising tobacco taxes to increase prices by 10% reduces tobacco use by 4% in high-income countries, and by 5% in low and middle-income countries, as the World Health Organization has suggested, what is the elasticity of demand for tobacco use in those countries? M