Working Paper Abstract
Platform Competition Through Composition: Engagement Heterogeneity, Data Accumulation, and Market Tipping
Abstract
This paper studies how smaller platforms can overtake larger rivals when user composition matters as much as user count. A platform with an early sorting advantage among high-engagement producers can accumulate data faster, improve quality sooner, and cross a tipping threshold that leads to dominance. The mechanism is not scale alone but the interaction between design quality and the engagement composition of the user base.
Three results follow. First, conditional on early producer sorting, the platform whose design-composition product exceeds its rival’s can win from any equal or better starting position. Second, greater engagement heterogeneity lowers the tipping threshold and implies a cross-market association between contribution inequality and concentration. Third, concentration has distributional welfare effects: producers may benefit from quality improvements while consumers bear mismatch costs. The framework suggests caution with uniform policy thresholds because user count can understate or overstate competitive pressure depending on engagement composition. It also points toward engagement-contingent interventions as a possible design principle for digital-platform regulation and competition policy.
Keywords: platform competition, data accumulation, engagement heterogeneity, market tipping, concentration, digital platforms