Question 54

The four-firm concentration ratio is calculated by adding the market shares of the four largest firms.

The four-firm concentration ratio provides a measure of market concentration by summing the market shares of the largest four firms in an industry, reflecting their combined dominance.

A) By multiplying the squares of the market share of each firm

This option is incorrect because the calculation of the four-firm concentration ratio does not involve squaring the market shares. Instead, it simply adds the market shares of the largest four firms.

B) By multiplying the market shares of the four largest firms

This option is also incorrect. The concentration ratio is not calculated through multiplication; it requires the addition of the market shares of the top four firms instead.

C) By adding the squares of the market share of each firm

While this option suggests an addition process, it incorrectly states that squares of the market shares should be added. The concentration ratio specifically focuses on the actual market shares of the four largest firms without squaring them.

D) By adding the market shares of the four largest firms

This is the correct method for calculating the four-firm concentration ratio. It directly assesses how much of the market is controlled by the largest firms, providing insight into market structure and competition.

Conclusion

The correct answer, D, is definitive as it accurately describes the method for calculating the four-firm concentration ratio by summing the market shares of the four largest firms. Options A, B, and C fail to reflect the correct approach, focusing instead on incorrect mathematical operations that do not apply to this specific measure of market concentration.