Using Online Crowdsourcing to Measure Judicial Attitudes of Domestic Courts Toward the Court of Justice of the European Union

Empirical research on judicial practices and attitudes towards European integration is hampered by the scarcity of data and the challenges involved in collecting information across 28 national legal systems. We undertake to overcome these problems by leveraging the knowledge of legal experts and court watchers throughout the EU. We use an expert crowdsourcing survey design to construct indicators of the attitudes and practices of 70 peak courts regarding EU law and European integration. Applying a purposive sampling strategy, we reached out to experts who have been active participants in the domestic application of EU law and are familiar with the practices of their domestic courts. Translated in 21 languages, our questionnaire was distributed as an online survey to around 9000 legal experts across all EU-28 member states. 587 questionnaires were completed between late March and early August 2017. Survey questions covered domestic judicial attitudes, the application of EU regulations and legal doctrines by domestic courts, practices regarding the preliminary reference procedure and positioning vis-à-vis domestic and EU institutions. Questions regarding the position of the German Federal Constitutional Court, which is particularly salient in European legal discourse, served as a baseline to facilitate cross-country comparison of expert opinions. Preliminary results reveal significant differences across countries and court types. Contrary to claims often made by legal scholars, we find that judicial attitudes towards legal integration do not conform to systematic regional patterns nor correlate with the subject matter jurisdiction of the court. Leveraging the wisdom of expert crowds, our online survey offers an alternative method to gather empirical data in an area which has traditionally been impervious to empirical investigation. Because of its aim to propose a new empirical tool for evaluation of judicial attitudes of domestic courts in the process of EU legal integration, we suggest that the paper would fit well in the ‘Judicialization of politics and politicization of courts’ panel.