NBER Publications by Dietmar Harhoff

The recent surge in U.S. patenting and expansion of patentable subject matter has increased patent office backlogs and raised concerns that in some cases patents of insufficient quality or with inadequate search of prior art are being issued. At the same time patent litigation and its costs are rising. This paper explores the potential of a post-grant review process modeled on the European opposition system to improve patent quality, reveal overlooked prior art, and reduce subsequent litigation. We argue that the welfare gains to such a system may be substantial.

We report the results of the first comparative study of the determinants and effects of patent oppositions in Europe and of re-examinations on corresponding patents issued in the United States. The analysis is based on a dataset consisting of matched EPO and US patents. Our analysis focuses on two broad technology categories - biotechnology and pharmaceuticals, and semiconductors and computer software. Within these fields, we collect data on all EPO patents for which oppositions were filed at the EPO. We also construct a random sample of EPO patents with no opposition in these technologies. We match these EPO patents with the 'equivalent' US patents covering the same invention in the United States. Using the matched sample of USPTO and EPO patents, we compare the determinants of opposition...

Much of the current discussion promoting apprenticeship programs in the U.S. proceeds as if it is simply a matter of historical accident or lack of imagination which has hindered human capital investment by U.S. firms. However, the cause may be rooted more deeply in our labor market institutions. This paper discusses the structure of incentives undergirding the German system of apprenticeship training. Many German firms face large net costs of apprenticeship training. Yet they continue to provide such training in spite of considerable worker turnover upon completion of the training. The simplest human capital model suggests that employers would be willing to finance only firm-specific training. Rather than engage in a futile debate over the general or specific nature of the skills be...