EVIDENCE AND INFERENCE IN THE COMPARATIVE CASE-STUDY

Comparative case studies often rely on the analysis of a few cases sel ected on the dependent variable. This approach has been criticized in the methodological literature. I offer a qualified defense of the meth od. Selecting on the dependent variable is appropriate when necessary conditions are being evaluated. Works that have been criticized for se lecting on the dependent variable make appropriate claims about necess ary conditions. Evaluation of the inferential problems suggest guideli nes for case selection and analysis. In particular, a simple Bayesian model can question whether comparative case studies necessarily suffer from a ''small n'' problem. Necessary conditions are an important, if undervalued, tool of political analysis.