Many outspoken critics of the current patent system have argued that the decline in the quality of patents could undermine the competitiveness of the national economy. In recent years, these arguments have begun to focus attention on the role of examiners in the patent process. If examiners differ from each other in how they approach applications, then they introduce arbitrariness into the process. In this article, Professor Mann offers a deeper look into this idiosyncrasy among patent examiners. Using data collected by the National Bureau of Economic Research and by the Patent Office itself, Professor Mann is able to come to three important conclusions. First, that past scholarly articles have overemphasized the importance of an examiner’s experience. Second, that the effects of tenure substantially affect the quality of the patents that an examiner produces. Finally, that education affects the work of examiners in important ways.