In the 1990s Goldthorpe concentrated mainly on theoretical and methodological issues, in particular on the understanding of social causation and, relatedly, on the application of rational action theory in the explanation of the probabilistic empirical regularities typically established through large-scale social survey research. As an illustration, he produced, together with Richard Breen, a rational action model of class-linked differences in educational choice, which has been widely tested and discussed.  He also worked with Robert Erikson and Michelle Jackson on ‘primary’ and ‘secondary’ effects in the creation of educational inequalities and, with these colleagues and in collaboration with David Cox, proposed statistical methods for distinguishing between the two and determining their relative importance.