European Constitutional Court Network (ECCN)

Constitutions contain the most important rules of our political systems and Constitutional Courts are the most powerful judicial institutions of European states. They are the guardians of the Constitutions and ensure, for instance, the respect for fundamental rights. Since the 20th century their importance is ever growing, which attracted a lot of interest from academia and beyond. Yet, despite numerous investigations, we know little about how different Constitutional Courts refer to each other. With the ECCN project, the researchers want to tackle this research gap.

It is now broadly understood that Constitutional Court decisions rarely form in a vacuum. Sometimes European Constitutional Courts rely on judgements from other European Constitutional Courts. Yet, more work is necessary to explore the extent of this phenomenon. In the ECCN project, the research team will measure empirically, if, and if yes how often, say, the Austrian Constitutional Court quotes or simply adopts the reasoning of other European Constitutional Courts such as for instance the German, the Polish or the Spanish Constitutional Court.

After exploring the direct and indirect quotations of European Constitutional Courts, the project team analyzes potential reasons for quoting other Constitutional Courts. The fact that European Constitutional Courts sometimes refer to other Constitutional Courts is interesting, because theoretically a Constitutional Court should refer in its decisions only to the Constitution and not to other Constitutional Courts. By analyzing the ECCN with computational methods, the project team wants to find reasons for this phenomenon.

Due to the big and multilingual corpus of the different European Constitutional Court decisions from 1952 to today, this task is challenging. For a single person it would be very difficult to compare all decisions of European Constitutional Courts, because of all the different European languages and the mere quantity of texts. Yet, the research team uses modern computational methods to carry out the analysis. More specifically, the team relies on their expertise in automated text analysis methods to tackle this task. Beyond the measurement of the citation network, that is the network of direct quotes between Constitutional Courts, machine learning allows them to generate a network of semantic text similarities. Both, citations and semantic text similarity, can be measured in texts with varying languages.

After digitalizing the ECCN, the following task is to explore conditions that explain patterns in this network. Hence, once the team has measured the network, they aim at explaining their results using inferential network analysis. With this approach, they do not only create original data, but also test established theories in a sophisticated and innovative way. In short, the project team digitalizes and explains the network of European Constitutional Court decisions.