Abstract
The article argues that a mechanism-based approach is a promising way for comparative analyses of social policy developments, as it allows to focus on specific sequences within broader processes, and to draw inspiration from elements of different theoretical approaches to explain these sequences. The article analyses the developments of the social insurance pension system in Vietnam and the national provident fund in Sri Lanka, which present two variants of a contribution-based pension system. Despite different starting points and institutional and economic backgrounds, the article reveals that both countries are characterised by maintenance and expansion of their pension systems on the policy level, and limitations in expanding effective coverage on the implementation level. We identify three causal mechanisms that are crucial for understanding these developments: The policy-areas-interdependence mechanism explains how, in an integrated political system, policies are being maintained despite dysfunctions, because they have important stabilizing functions for other policy areas. The evasion mechanism explains how national policy actors on the surface follow International Organisations’ recommendations and support further cooperation, while conducting reforms in line with national political considerations. The limited-compliance mechanism explains how reforms that are being adopted on the policy level are not being implemented.