Migration regulations have increasingly become a politicized area of policy, requiring policymakers to respond to evolving societal and economic dynamics. Despite this focus, the policy portfolios of Western destination countries exhibit remarkable stability over time, suggesting migration policy is a saturated field with few new policy target groups and limited innovative measures. This research investigates mechanisms of change within this saturated environment.

This study analyzes the immigration and integration policies of ten OECD countries from 1975 to 2020, leveraging a novel dataset for detailed cross-country comparisons. By examining patterns in policy instruments for specific immigrant admission categories, it identifies similarities, divergences, and distinctive national approaches. Simultaneous analysis of immigration and integration policies reveals a comprehensive picture of each country's migration policy framework.

A key finding is the differential saturation between immigration and integration portfolios. The majority of countries have integration portfolios that are less saturated, with notable variation between them. Notably, countries with less sophisticated integration policy frameworks also tend to make fewer adjustments to existing measures. Despite the stability of the overarching policy framework, an increase in fine-grained changes is observed at both policy levels across countries. This results in a rise in regulatory complexity. These findings underscore significant variations and enhance our understanding of migration policy dynamics.

This work addresses a critical gap in the literature by unifying immigration and integration frameworks in a holistic analytical model. Moving beyond restrictiveness or temporal trends, it identifies overlooked patterns and shifts, enhancing insights into how countries navigate migration governance.