4. a proposal for a negative income tax is designed to provide an income guarantee for each person, irrespective of his age or status, of $3,000 per year. Thus, a family of four would have an income guarantee of $12,000 per year. The transfers under the program will be phased out at a rate of 25 percent as earned income increases. Calculate the break-even level of income for a family of four. If all families above the break-even level of income pay a flat-rate 25 percent tax on their earnings, plot disposable income as a function of earned income. Comment on the costs of this plan