Answer: neither the concentration ratio nor the Herfindahl-Hirschman index.

## Explanation Both the concentration ratio and the Herfindahl-Hirschman Index (HHI) are measures of market concentration that focus on **existing firms** in an industry. They do **not** consider the possibility of new entrants. ### Key Points: 1. **Concentration Ratio**: Measures the percentage of market share held by the largest N firms (typically 4 or 8 firms). It only looks at current market participants. 2. **Herfindahl-Hirschman Index (HHI)**: Calculated by summing the squares of the market shares of all firms in the industry. Like the concentration ratio, it only considers existing firms. 3. **New Entrants**: The threat of new entrants is part of Porter's Five Forces analysis, which examines competitive forces in an industry. This is a qualitative assessment, not captured by quantitative concentration measures. 4. **Limitations of Concentration Measures**: Both CR and HHI have limitations: - They don't account for potential competition - They don't consider geographic market boundaries - They don't account for product differentiation - They assume market shares accurately reflect competitive pressure Therefore, the correct answer is **C** - neither measure considers the possibility of new entrants.

Author: LeetQuiz .