Georg von Graevenitz

Incidence and Growth of Patent Thickets - The Impact of Technological Opportunities and Complexity

We investigate incidence and evolution of patent thickets. Our empirical analysis is based on a theoretical model of patenting in complex and discrete technologies. The model captures how competition for patent portfolios and complementarity of patents affect patenting incentives. We show that lower technological opportunities increase patenting incentives in complex technologies while they decrease incentives in discrete technologies. Also, more competitors increase patenting incentives in complex technologies and reduce them in discrete technologies. To test these predictions a new measure of the density of patent thickets is introduced. European patent citations are used to construct measures of fragmentation and technological opportunity. Our empirical analysis is based on a panel capturing patenting behavior of 2074 firms in 30 technology areas over 15 years. GMM estimation results confirm the predictions of our theoretical model. The results show that patent thickets exist in 9 out of 30 technology areas. We find that decreased technological opportunities are a surprisingly strong driver of patent thicket growth.

Conflict Resolution, Public Goods, and Patent Thickets

Postgrant validity challenges at patent offices rely on the private initiative of third parties to correct mistakes made by patent offices. We hypothesize that incentives to bring postgrant validity challenges are reduced when many firms benefit from revocation of a patent and when firms are caught up in patent thickets. Using data on opposition to patents at the European Patent Office we show that opposition decreases in fields in which many others profit from patent revocations. Moreover, in fields with a large number of mutually blocking patents, the incidence of opposition is sharply reduced, particularly among large firms and firms that are caught up directly in patent thickets. These findings indicate that postgrant patent review may not constitute an effective correction device for erroneous patent grants in technologies affected by either patent thickets or highly dispersed patent ownership. This paper was accepted by Lee Fleming, entrepreneurship and innovation .

Trade mark cluttering–evidence from EU enlargement

This paper exploits enlargement of the European Union as a natural experiment to provide evidence for cluttering of the trade mark register in Europe. Enlargement increased regulatory uncertainty for pharmaceutical firms because the number of medical regulators that had to approve invented names for pharmaceutical products increased sharply at the time. The effects of this regulatory shock on pharmaceutical firms’ trade mark application strategies are studied using Difference-in-Differences and bias adjusted matching estimators. It is shown that enlargement had a significant and quantitatively important effect on pharmaceutical firms’ incentives to clutter trade mark registers with trade marks they are unlikely to use.

Conflict Resolution, Public Goods and Patent Thickets

Post-grant validity challenges at patent offices rely on the private initiative of third parties to correct mistakes made by patent offices. We hypothesize that incentives to bring post-grant validity challenges are reduced when many firms benefit from revocation of a patent and when firms are caught up in patent thickets. Using data on opposition against patents at the European Patent Office we show that opposition decreases in fields in which many others profit from patent revocations. Moreover, in fields with a large number of mutually blocking patents the incidence of opposition is sharply reduced, particularly among large firms and firms that are caught up directly in patent thickets. These findings indicate that post-grant patent review may not constitute an effective correction device for erroneous patent grants in technologies affected by either patent thickets or highly dispersed patent ownership.

Does Online Search Predict Sales? Evidence from Big Data for Car Markets in Germany and the UK

We use online search data to predict car sales in the German and UK automobile industries. Search data subsume several distinct search motives, which are not separately observable. We develop a model linking search motives to observable search data and sales. The model shows that predictions of sales relying on observable search data as a proxy for prepurchase search will be biased. We show how to remove the biases and estimate the effect of pre-purchase search on sales. To assist identification of this effect, we use the introduction of scrappage subsidies for cars in 2008/2009 as a quasi-natural experiment. We also show that online search data are (i) highly persistent over time, (ii) potentially subject to permanent shocks, and (iii) correlated across products, but to different extent. We address these challenges to estimation and inference by using recent econometric methods for large N, large T panels.