US multinationals fatten their bottom lines by arbitraging wages, taxes, and regulations across countries.

Bond rating agencies found it hard to serve both the interests of bond investors and bond issuers since they were directly paid by bond issuers for favorable ratings.

Merger between firms making complementary components might be anti-competitive if the merged company can price their bundled products lower than the independent component makers.

Legacy habit of central planning has led to antitrust charges against Chinese vitamin C oligopoly.

Mature oligopoly with a few large producers of homogeneous commodities is driven to output and price fixing to increase their profit.