What type of market imperfection occurs due to monopoly power?

Monopoly power leads to market imperfections primarily because a single firm or entity controls a significant portion of the market, allowing it to influence prices and output levels. When a monopoly exists, the typical mechanisms of competition—such as price adjustments in response to supply and demand—are disrupted. This often results in inefficiencies, specifically allocative inefficiency, because the monopolist can set prices above the marginal cost of production. This means consumers pay more and can buy less than they would in a competitive market, reducing overall consumer welfare.

The inefficiencies typically observed in a monopoly may prompt government intervention. Various regulatory measures may be implemented to control prices, increase competition, or curb the monopolist's power to protect consumer interests and restore market efficiency. In this context, the presence of monopoly power creates a situation where market inefficiency is prevalent, leading to potential government regulations aimed at correcting the imbalance and promoting competition.

Other options describe concepts that do not relate directly to the consequences of monopoly power. For example, price efficiency and market equilibrium suggest optimal market conditions that are usually absent in monopolistic situations. Likewise, consumer surplus maximization implies an ideal scenario where consumer welfare is at its highest, which is not achievable under a monopoly due to higher prices and reduced output.