Mapping European Law: The Evolving Subnational Reception of the Preliminary Reference Procedure

This article constitutes the first systematic effort to analyze the subnational reception of European Union (EU) law across time and space by uncovering the local, contextual factors that shape the emergence, path-dependence, and diffusion of domestic courts’ use of the preliminary reference procedure. Theoretically, we build upon the literatures on (1) the “judicialization” of European politics and (2) policy diffusion by synthesizing them into a historical institutionalist framework amenable to explicating the temporal and spatial structure of preliminary reference rates. Empirically, we leverage Geographic Information Systems (GIS) technology for the first time to map preliminary references originating from Italy, France, and Germany from the late 1950s through the present and visualize the temporal variance in the spatial autocorrelation of EU litigation. We complement GIS analysis with regression analysis and case studies of select regions to unearth both the macro-historical trends as well as the contingent causal processes at work. We conclude that such a spatially conscious, incrementalist historical institutionalist approach promises to revolutionize the study of EU legal integration and overcome the limitations of both the large-N, country-level quantitative studies and qualitative case-law histories available to date.