This paper offers an integrated theoretical and empirical model of return enforcement as a strategic interaction between EU+ countries and third countries. We develop a game-theoretic model in which EU+ states choose enforcement effort and third countries choose acceptance willingness based on costs, benefits, reciprocity, and normative alignment. We show how different strategic logics (complementarity, deterrence, threshold effects) combined with normative alignment can explain observed variations in return outcomes. Based on this theoretical model, we construct two empirical analyses that examine: (1) the policy and non-policy determinants of return outcome and (2) the behavioural feedback effects of non-enforcement on irregular migration flows. We rely on harmonized panel datasets at the dyadic and country-year levels, integrating return data, bilateral trade, governance indicators, and migration flows.
Czaika et al. (Tue,) studied this question.