Large digital platforms have evolved into vast multimarket/multiproduct conglomerates, both organically and through a decade-long acquisition spree. Conduct and mergers can no longer be evaluated “market-by-market.” Yet the antitrust assessment of these “ecosystems” is still in its infancy, and regulators seeking to explore harm arising from the control of multiple assets and capabilities are falling back on traditional theories of harm that are more likely to resonate with judges. Su...
