4. U .S. Steel Corporation supplies between 20 and 30 percent of the total domestic market of steel . McGraw-Hill Book Company supplies nearly 50 percent of the total market for introductory economics texts. Do you think that the government should regulate the price of steel and/or introductory economics texts? Discuss the degree o f concentration, entry barriers, and "competitiveness" o f the two markets. Are concentration ratios always a good index of competitiveness? Why or why not?