Rule of Law Indices and How They Could Be Used in the EU Rule of Law Crisis

Since the early 2010s, and especially since the 10 June 2015 resolution of the European Parliament, there has been a growing interest in monitoring and measuring the rule of law in the Member States of the EU. Going beyond the available measurement tools in Europe, such as the EU Justice Scoreboard, we discuss the lessons taught by the construction of international indices on the rule of law. In addition to the traditional toolbox of a lawyer, we have to turn to other methods of social sciences and statistics in order to quantify the state of, as well as the changes and trends in the rule of law. The methodology regarding this topic has an extensive literature and we can enumerate manifold European and US American indices measuring the rule of law (e.g. Freedom House, Bertelsmann Stiftung, World Bank, World Justice Project). The present paper is a methodological introduction into rule of law indices, focusing on the terminology used, the collection and aggregation of data, the interpretation of the results and the comparison between countries and over time. Our purpose is to show how (and how far) these indices could be used in the current rule of law crisis of the European Union