Developments in the digital economy are challenging established approaches that authorities relied on to protect competition, ensure market confidence and promote social welfare. In this context, online platforms are changing markets, business models and economic competition in innovative and disruptive ways. As a result, the regulation of online platforms has become a priority for authorities, regulatory agencies, and policymakers. This report gathers the main findings and the best practices regarding competition assessment of online platforms in the APEC region; it explores the economics behind online platforms; and seeks to contribute to the debate of new approaches for competition analysis in the digital market, particularly on market definition, abuse of dominance and mergers. Finally, it outlines recommendations for the improvement of economic competition assessment of online platforms so that authorities can further develop policies and their legal frameworks, reshape their enforcement tools, and advocate for a competition-supportive and technologically neutral approach.