A Complexity-Based Approach to Migration Policy Change: The Case of the German Residence Act

This paper adapts and applies existing indicators to measure the complexity of German migration policy over time. Building on recent scholarship that conceptualizes migration policy as multidimensional, I adapt a measurement strategy from the EUPLEX Project to capture three key components of regulatory complexity: structural, linguistic, and relational. Using an original dataset (COMPLEXMIG), I apply quantitative text analysis to all versions of the German Residence Act from 2005 to 2023. The analysis examines both the overall evolution of complexity in German migration policy and the differences in complexity across specific migration pathways—labor, family, humanitarian, and student migration. The results reveal that regulatory complexity does not evolve linearly but follows punctuated patterns of change, with moments of sharp increase concentrated in a few time periods. These findings contrast with the more gradual and diffuse changes observed in the substance of migration policy, suggesting that complexity operates as a distinct dimension of policy development. This study contributes methodologically by offering tools to systematically assess regulatory complexity and by demonstrating how complexity measures can illuminate temporal dynamics often overlooked in existing research. This approach lays the groundwork for future comparative analyses of how complexity shapes migration policy.