Publications
Doctoral Research
I am currently a doctoral researcher at the Oxford Internet Institute, University of Oxford.
My thesis examines whether, and under what conditions, digital platform interoperability can expand user choice in social networking markets. I analyse the Mastodon network as a real-world case of interoperability, drawing on novel large-scale datasets and mixed methods (statistics, NLP, network analysis).
My supervisors are Professor Greg Taylor and Professor Vili Lehdonvirta. My doctoral studies are supported by scholarships from the Heinrich Böll Foundation, St Catherine’s College Oxford, and the Oxford Internet Institute.
Under Review & Forthcoming
Research Article Under Review Preprint
Riederle, P. (2026). Does Digital Platform Interoperability Deliver on Its Expectations? Evidence From User Switching on Mastodon.
Preprint available (v2, 06 May 2026), currently under journal review.
☰ Abstract
Markets for online social networks (e.g., X, Instagram, Linkedin) tend to concentrate, leaving users with little choice: accept the conduct of dominant providers or forgo participation. Digital platform interoperability is widely proposed as a remedy to reduce the economic and political power of centralised platforms by enabling user choice without sacrificing network connectivity. Despite already being included in legal mandates and legislative proposals (e.g., EU Digital Markets Act, US Access Act), interoperability’s effects remain largely untested. This paper empirically evaluates three theoretical expectations about interoperability in social networking platforms. It analyses an original dataset on user switching within the interoperable Mastodon network through a sequential mixed-methods approach. I find evidence that interoperability can expand user choice and identify conditions under which it does so in social networking markets. To neutralise the role of proprietary network effects, interoperability needs to extend beyond ‘tie-based interactions’, familiar from legacy communication networks, to what this paper identifies as ‘open-network interactions’. Interoperability facilitates individual choice and switching, but frictions remain where ‘user assets’ are bundled to ‘provider services’, causing substantial information and switching costs. Contrary to concerns that technical standardisation homogenises services, interoperable providers differentiate vertically (e.g., quality) and horizontally (e.g., governance values), offering meaningful grounds for user choice. This paper’s findings have direct implications for ongoing policy processes and open a research agenda on the dynamics between interoperable but differentiated platform providers.
Book Chapter Forthcoming
Riederle, P., & Lehdonvirta, V. (forthcoming). Why Online Marketplaces Centralise: The Limits of Decentralised Internet Platforms. In P. Aspers, M. Dewey, J. Nyfeler, L. Perrig, & L. Pignolo (Eds.), The Oxford Handbook of Marketplaces. Oxford University Press.
Publication expected late 2026/early 2027. Working paper available upon request.
☰ Abstract
Despite the Internet’s decentralised technical architecture, online trade has centralised through dominant online marketplaces (also known as multi-sided markets or transaction platforms). Their dominance has provoked calls for regulatory intervention and ‘re-decentralisation’. This chapter explains why trade centralised and discusses the potential for decentralisation. We distinguish between two dimensions of centralisation. We explain why trade became intermediated by marketplaces despite the Internet’s peer-to-peer architecture and modular institutions: integrated marketplaces reduce transaction costs by bundling market organisation and establishing unified, enforceable governance. Next, we analyse why markets for marketplaces concentrate: their endogenous market structure favours scale, marketplace providers strategically manufacture their dominance, and governance becomes ineffective through fragmentation. Finally, we evaluate two types of interoperability as decentralisation mechanisms. Horizontal interoperability addresses market concentration, but risks fragmenting the authority that makes governance effective. Vertical interoperability enables a more functional separation, while preserving unified governance per transaction.
Earlier Research
Masters Thesis Unpublished
Riederle, P. (2023). Governance of Digital Platform Software - The Case of Development Contributions to the Fediverse. Masters Thesis, Oxford Internet Institute. Unpublished.
Available upon request.
Bachelors Thesis Unpublished
Riederle, P. (2021). Digital Start-up Founders’ STEM and Non-STEM Higher Education as Signals in Venture Capital Funding Decisions. Bachelors Thesis, Zeppelin University. Unpublished.
Available upon request.