Some of these cartels are well-known, like the Coke/Pepsi duopoly. Pepsi's bosses boasted to their shareholders about "Pepsi pricing power," and how they were able to raise prices over the inflationary increases caused by covid and the Russian invasion of Ukraine:
https://pluralistic.net/2023/03/11/price-over-volume/#pepsi-pricing-power
You might know that pretty much every packaged good in your grocery store is made by one of two companies, Unilever and Procter and Gamble.
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