One way to identify oligopoly is to
A) determine the market's minimum price.
B) determine the market's maximum price.
C) determine whether the firm's ATC exceeds price.
D) use the Herfindahl-Hirschman Index (HHI).
E) use the Efficiency test.

Question

Quizplus · Accepted Answer

The Herfindahl-Hirschman Index (HHI) is a common tool used to identify oligopoly. It measures the market concentration by summing up the squared market shares of each firm in the industry. Higher HHI indicates higher concentration, and a score above 2500 is often used as an indicator of oligopoly.

One Way to Identify Oligopoly Is to