Abstract

This paper explores the multi-level causal structure of complex systems of migration, emphasizing the challenge of multiscale phenomena inherent in such systems. It argues that complex systems display multiscale structures, with the meso-level acting as a critical bridge for the emergence of essentially novel properties. Initially, the paper confronts the dichotomy between micro- and macro-level models, underscoring the necessity of capturing meso-level causal processes. It proceeds to scrutinize the scale separation of causal variables in migration processes and introduces differing modeling approaches. By highlighting the limitations of classical models in addressing multiscale causality, the paper advocates for a complex-system approach. It argues that such an approach improves our understanding of migration processes’ multi-level structure. With a central focus on emergence, it offers a comprehensive analysis of the intricate causal structures within complex systems of migration, yielding original insights into the dynamic nature of migration phenomena.