In this paper we consider the properties of a simple test of parameter restrictions based on standard two-step efficient GMM estimators. The test is computed simply as the difference between the minimised values of the GMM criterion function in the restricted and unrestricted models. We compare...

The implementation of the 1950 Swedish comprehensive school reform was preceded by a unique social experiment. During this experiment between 1949 and 1962 the new school system was implemented in stages. This allows us to study the same cohort of individuals going through two different school...