Economists have a metric known as the “four-firm concentration ratio,” sometimes deployed in shorthand as “CR4.” It is a measure of competitiveness in a market for goods or services. When four companies gain a combined market share that is greater than 40 percent, an oligopoly has formed.
You are not logged in. However you can subscribe from another Fediverse account, for example Lemmy or Mastodon. To do this, paste the following into the search field of your instance: !canada@lemmy.ca
TIL https://en.wikipedia.org/wiki/Concentration_ratio