A Network Analysis of Judicial Cross-Citations in Europe

Abstract

Recent years have seen a growing literature on citations between courts from different countries. What explains why such cross-citations occur between some courts but not others? This article addresses this question with original data on 2,967 citations between the private law supreme courts of the twenty-eight member states of the European Union. These cross-citations form a valued network of twenty-eight nodes, which can be analyzed with tools of network analysis. The article uses the method of a multiple regression quadratic assignment procedure in order to address the dependency of observations in a network. The explanatory variables distinguish between variables that proxy for legal similarities between countries and other factors, and, thus, this article contributes to the wider debate about the predominance of either legal or nonlegal factors in judicial decision-making. The main finding is that nonlegal factors play a decisive role, notably a common native language and overlapping language skills, while legal families are not found to be a significant determinant.

Legal hypergraphs

“…In legal network analysis, inspired by the seminal work of [22], scholars have studied both information networks, such as judicial citation networks [19,20,[23][24][25][26] or legislation networks [14,16,27,28], and social networks, such as legislative collaboration networks [29][30][31] or judicial collaboration networks [32]. While most investigations have focused on individual countries [33][34][35][36], others have compared several countries [37,38], or studied networks at the European level [39][40][41][42] or the international level [43][44][45][46]. Although researchers are increasingly using temporal graphs in their modelling [47,48], they have yet to systematically consider higher-order interactions, as has recently been done in other domains [49].…”