The effectiveness of immigration policies: A conceptual review of empirical evidence
Mathias Czaika , Hein de Haas
In the face of the apparent dispute in migration research about the effectiveness of migration policy, this paper scrutinizes the nature, evolution and effectiveness of immigration policies and provides an analytical framework for future research. In order to reduce analytical confusion and reconcile apparently conflicting views, this paper defines what constitutes migration policy and distinguishes policy effectiveness and policy effects. It identifies three policy gaps which can explain perceived or real policy failure. First, the ‘discourse gap’ is the considerable discrepancy between the stated objectives of general public migration discourses and concrete policies. Second, the ‘implementation gap’ is the disparity between policies on paper and their actual implementation. Third, the ‘efficacy’ gap is the extent to which an implemented policy has the capacity to affect migration flows. The paper argues that studies should use concrete policies rather than public discourses as the evaluative benchmark. While we question the received idea that immigration policies have necessarily become more restrictive, available evidence suggests that migration policies have a significant effect on migration, but that the effect is limited compared to other migration determinants. Their effect might be further limited through various spatial, categorical and inter-temporal ‘substitution effects’. The paper hypothesizes that policies seem more effective in determining the selection and composition of migration rather than the overall volume and long-term trends of migration. However, robust evidence is still scarce and existing studies are generally unable to test for various ‘substitution effects’. The paper also suggests conceptual and methodological avenues for improving insights into policy effectiveness and effects.