Question

Which of these industries has not been considered a natural monopoly in the past 30 years?


diamonds


electricity


water


phone service

Answer 1

Among the industries listed, **diamonds** has not been considered a natural monopoly in the past 30 years. Natural monopolies typically occur in industries where high infrastructure costs and other barriers to entry prevent competition, which is true for electricity, water, and phone service. In contrast, diamonds are part of a market where multiple companies can operate independently, and there is competition among different producers and sellers.