Density dependence without resource partitioning on an online petitioning platform

Abstract

Online petitions are a collective action tactic that leverages digital affordances in pursuit of discursive opportunities. Prior efforts to explain why some petitions are more successful than others emphasize signer motivations, petition framing, social media, or resources from movement organizations. We advance a key insight of organizational ecology: population-level variables like density and concentration also constrain success. We use latent Dirichlet allocation (LDA) topic models to measure overlap density and frame specialization. We then model how ecological dynamics affect petition signature counts. We observe density dependence: a curvilinear relationship between overlap density and success. We anticipated resource partitioning: specialists enjoy competitive advantages under concentration, but we find no evidence for it. We discuss boundary conditions for ecological dynamics commonly found in organizational fields induced by the distinctive scope of e-tactic platforms. Platforms may produce concentration without advantages for specialists by lowering entry costs for generalists and specialists alike.