Although theirs is a case-study approach, within the case studies the authors conduct rigorous statistical analyses to isolate the various effects on wage determination. They test multivariate models that seemingly control for at least a defensible set of alternative explanations for wages. I am convinced by their findings that the court, and even at times the plaintiffs in the case, overlooked some interesting analyses that may have changed the outcome of the cases. A really smart plaintiff might consider hiring the pair as expert witnesses. There are places in the book where the analysis does not exactly speak to the conclusions the authors' draw.
Some inferences also appear to be unjustified.
The authors are most certainly convinced that between-job discrimination is an evil to be fought and so at times tend to make more of the results than may be warranted. Although many of the results of the case studies are indisputable, there seems to be an overall exaggeration of the importance of the differences encountered and an attribution of these differences to the management of these companies and their devaluation of female jobs. Sometimes I am totally convinced that the court missed a glaring difference between jobs. Other times I believe that even were these authors to present their data, the court would have decided as it did. It also seems to me that, given their interest in social science data presented to the court as well as the treatment of that data by the court, they should have discussed the acceptance of and reliance upon social science data by courts generally.