This article presents HUNCOURT, a complex open legal database for the quantitative analysis of the practice of the Hungarian Constitutional Court (HCC). Covering all HCC decisions and orders published between 1990 and 2021, the new database is published under an Open Database License and allows for advanced queries that go beyond the search engine options of industry-standard proprietary legal databases. We bypass the often inaccurate and time-consuming manual search options by providing a full text database that is entirely machine-readable, along with a full selection of available metadata. In the article, we also demonstrate the potential of the new database for scholarly research by presenting a use case for such analysis related to the self-reflexivity and reasoning of the constitutional court. We show that a state-of-the-art database opens up possibilities for applying quantitative text analysis and text mining to research questions that have so far been mostly analysed in a qualitative framework.

While the stability of legislation is one of the fundamental issues in political theory, comparative and quantitative analyses on the subject are in short supply in the political science literature. In this article, we propose a novel measurement scheme for legislative stability, and we also introduce a Legislative Stability Index (LSI) developed to this end. In terms of empirical evidence, our index relies on the number of legislative amendments adopted within the span of an electoral cycle, as well as the breadth of issues the amendments touch on. It is based on the frequency with which laws are amended after their adoption. Our approach uses a new law-amendment edge-type network for a new Hungarian legislative database. Amendment-type connections are discovered by an automated dictionary-based text mining method. We tested the applicability of our index in various regression models. Results show that the legislative term, the length of the law and the way it was adopted were the most significant variables in explaining variation in the stability of legislation.