Editing Concentration ratio (section)

== Calculation ==
The concentration ratio is calculated as follows: <ref name="besanko">{{cite book|last=Besanko|first=David|date=2017-07-01|title=Economics of Strategy|url=https://www.wiley.com/en-us/Economics+of+Strategy%2C+7th+Edition-p-9781119042310|publisher=Wiley|page=162|isbn=978-1-119-04231-0}}</ref>
<math display="block">\text{CR}_n = C_1 + C_2 + \cdots + C_n = \sum\limits_{i=1}^n C_i</math>
where <math>C_i</math> defines the market share of the <math>i</math>th largest firm in an industry as a percentage of total industry market share, and <math>n</math> defines the number of firms included in the concentration ratio calculation.

The <math>\text{CR}_4</math> and <math>\text{CR}_8</math> concentration ratios are commonly used. Concentration ratios show the extent of largest firms' market shares in a given industry. Specifically, a concentration ratio close to 0% denotes a low concentration industry, and a concentration ratio near 100% shows that an industry has high concentration.