The power of digital platforms is at the center of major ongoing policy and regulatory efforts. To advance existing debates, we designed and executed an experiment to measure the performative power of online search providers. Instantiated in our setting, performative power quantifies the ability of a search engine to steer web traffic by rearranging results. To operationalize this definition we developed a browser extension that performs unassuming randomized experiments in the background. These randomized experiments emulate updates to the search algorithm and identify the causal effect of different content arrangements on clicks. Analyzing tens of thousands of clicks, we discuss what our robust quantitative findings say about the power of online search engines, using the Google Shopping antitrust investigation as a case study. More broadly, we envision our work to serve as a blueprint for how the recent definition of performative power can help integrate quantitative insights from online experiments with future investigations into the economic power of digital platforms.

As part of the European Commission's broader data strategy, the Data Governance Act (“DGA”) introduces a new regulatory regime for data intermediaries, which, inter alia, pursues the objective of increasing the competitiveness of the European data economy by bolstering trust in data-sharing mechanisms. Against this backdrop, we introduce data intermediaries and critically examine the DGA's related legal regime by testing its underlying assumptions and highlighting its intrinsic weaknesses and limitations as part of the broader EU data law puzzle. As a result, the paper brings to the fore certain contradictions between DGA's means and ends. Indeed, due to various questionable assumptions, the DGA imposes requirements that not all data intermediaries can satisfy and entrenches a specific techno-organisational form for data intermediation services that may turn out to be economically non-viable. Consequently, one must wonder whether the DGA's rules on data intermediaries are necessary and proportionate in light of the freedom to conduct a business. We furthermore uncover inconsistencies and loopholes between the DGA, the GDPR, the draft Data Act, and the Digital Markets Act. Overall, while the DGA's underlying efforts are laudable, its precise postulations may hinder the achievement of its underlying objectives due to two main factors. First its own internal limitations and incoherences, and, second, uncertainties and tensions resulting from its interplay with the broader EU data law framework.