Prerequisites Versus Diffusion: Testing Alternative Explanations of Social Security Adoption

Cross-national research has, with a few exceptions, dealt exclusively with hypotheses that focus on causal relations within nations. It is increasingly clear both on substantive and methodological grounds, however, that diffusion effects among nations must also be considered. The present research combines these alternative perspectives in an analysis of the timing of the first adoption of social security in nations. It is found that not only prerequisites explanations—which focus on causes within each nation—but also spatial and hierarchical diffusion effects must be considered in explaining patterns of social security adoption. The most important overall pattern, which appears to result from diffusion, is the tendency for later adopters to adopt at lower levels of modernization. This finding is interpreted as being due in part to a general tendency toward a larger role of the state in later developing countries—involving an important difference in thesequencein which different aspects of modernization occur—and in part to special characteristics of social security as a public policy.