Which statement describes the concentration ratio in an industry?

A high concentration ratio in an industry indicates that a small number of firms control a significant portion of the market. This typically means that these few firms hold substantial market power, allowing them to influence prices and output levels. In such cases, the market may be less competitive, leading to outcomes such as higher prices for consumers and less choice in the marketplace.

This concept is essential in analyzing market structures. For example, in industries characterized by oligopolies, where only a few firms dominate, a high concentration ratio reflects a scenario where these firms may engage in collusive practices to maximize profits. As a result, the market dynamics can heavily favor the dominant firms at the expense of consumer welfare.

Understanding concentration ratios helps economists and policymakers assess how competitive an industry is and the implications for consumer choice and pricing power. Thus, the assertion that a high concentration ratio shows a small number of firms control most of the market accurately captures the implications of market structure within microeconomics.