Although 23 states barred the sale of self-service gasoline in 1968, most removed the bans by the mid-1970s. By 1992, self-service outlets sold nearly 80% of all U.S. gas, and only New Jersey and Oregon continued to ban self-service sales. Johnson and Romeo (2000) estimated that the ban in those two states raised the price of gasoline by approximately 3¢ to 5¢ per gallon. Why did the ban affect the price? Illustrate using a figure and explain. Show the welfare effects in your figure. Use a table to show who gains and who loses.