Nairobi, June 30 -- Competition law and policy enforcers consistently face challenges in understanding the economic forces that drive competition in digital platform markets. Specifically, regulators struggle to draw clear market boundaries using conventional tools, because these platforms serve multiple groups of users at once, such as advertisers and consumers, and a price change on one side of the market often ripples through to the other, where the firm may not be dominant.

Perhaps the biggest challenge is measuring market power itself. The usual yardsticks, price sensitivity, market shares, and the ability of consumers to switch to competitors, do not easily translate in multisided markets. What may seem perfectly competitive on one...