Indicating which barrier to entry appropriately explains why a monopoly exists in each scenario? a. The Aluminum Company of America (Alcoa) formerly controlled all U. S. sources of bauxite, a key component in the production of aluminum. Given that Alcoa did not sell bauxite to any other companies, Alcoa was a monopolist in the U. S. aluminum industry from the late 19th century until the 1940s.
b. In order to own and operate a taxi, drivers are required to obtain a taxi medallion.
c. In the natural gas industry, low average total costs are obtained only through large-scale production. In other words, the initial cost of setting up all the necessary pipes and hoses makes it risky and, most likely, unprofitable for competitors to enter the market.