The Greens and the Smiths live in a state that has a proportional sales tax. Read the following details about each family. Then on a separate sheet of paper, write a short essay explaining the regressive effect of this proportional sales tax on each family. The Greens, a family of four, earns $20,000 a year and spends 70 percent of their income on taxable consumer goods. The Smiths, also a family of four, earns $200,000 a year, enough to allow them to invest or save 30 percent of their incomes. They spend only 40 percent of their income on taxable consumer goods.