Publications

Digital technologies have reduced the cost of collecting detailed information on consumer characteristics and behavior. Despite the large literature on the consequences of using these data to personalize prices, little is known about content personalization. Using detailed player-level data from a mobile puzzle game and a novel structural model of player behavior, we investigate the effects on revenue of personalizing game difficulty using observable player characteristics. Our results show that, while average difficulty across players is successfully set by the game developer to maximize revenue, personalization can further increase revenue by 71%. Personalized difficulty leads to an overall increase in player engagement and, consequently, revenue generation in the form of in-app purchases.

Markush structures are molecular skeletons containing not only specific atoms but also placeholders to represent broad sets of chemical (sub)structures. As genus claims, they allow a vast number of compounds to be claimed in a patent application without having to specify every single chemical entity. While Markush structures raise important questions regarding the functioning of the patent system, innovation researchers have been surprisingly silent on the topic. This paper summarizes the ongoing policy debate about Markush structures and provides first empirical insights into how Markush structures are used in patent documents in the pharmaceutical industry and how they affect important outcomes in the patent prosecution process. While not causing frictions in the patent prosecution process, patent documents containing Markush structures have an increased likelihood to restrict the patentability of follow-on inventions and to facilitate the construction of patent fences around original drugs.

Pharmaceutical firms enjoy market exclusivity for new drugs from concurrent patent protection and exclusivity of the clinical trials data submitted for market approval. Patent invalidation during drug development renders data exclusivity the sole source of protection and shifts the period of market exclusivity. In instrumental variables regressions, we quantify the effect of a one-year reduction in expected market exclusivity on the likelihood of drug commercialization. The effect is largely driven by patent invalidations early in the drug development process and by the responses of large originators. We provide estimates of the responsiveness of R&D investments to market exclusivity expectations.

Companies go to great lengths to keep some employees from leaving to work for rivals. Aside from offering benefits, they often rely on non-competes, trade secret protection and other legal means to avoid losing important talent and letting knowledge get into the hands of competitors. But our research suggests that companies might actually benefit from certain employees going to work for others in the same space.

We link the hiring of research and development scientists from industry competitors to the subsequent formation of collaborative agreements, namely technology-oriented alliances. By transferring technological knowledge as well as cognitive elements to the hiring firm, mobile inventors foster the alignment of decision frames applied by potential alliance partners in the process of alliance formation, thereby making collaboration more likely. Using data on inventor mobility and alliance formation among 42 global pharmaceutical firms over 16 years, we show that inventor mobility is positively associated with the likelihood of alliance formation in periods following inventor movements. This relationship becomes more pronounced if mobile employees bring additional knowledge about their prior firm's technological capabilities and for alliances aimed at technology development rather than for agreements related to technology transfer.

Patent-based measures are frequently used as indicators in empirical research on innovation and technological change. Currently, there is little evidence as to what extent patent-based indicators relate to product market outcomes. Using a unique dataset that links outcomes from product commercialization in the pharmaceutical industry with detailed patent data, we relate patent-based indicators that capture either an invention's value or the uncertainty surrounding the patenting process to the outcomes of the product development process. Our findings suggest that the speed of commercialization increases with value but reduces with uncertainty. Using a variety of alternative indicators we derive implications for the use and the proper interpretation of individual measures. Moreover, our study has broader implications as it highlights the detrimental effect of uncertainty on the speed of innovation.

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.

The literature on organizational learning asserts that external learning is often limited geographically and technologically. We scrutinize to what extent organizations acquire external knowledge by accessing external knowledge repositories. We argue that professional service firms (PSFs) grant access to nonlocalized knowledge repositories and thereby not only facilitate external learning but also help to overcome localization. Focusing on patent law firms, we test our predictions using a unique dataset of 544,820 pairs of EP patent applications. Analyzing patterns of knowledge flows captured in patent citations we find that accessing a PSF's repository facilitates the acquisition of external knowledge. As the effect is more pronounced for knowledge that is distant to a focal organization we conclude that having access to a knowledge repository compensates for localization disadvantages.

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.

This paper provides an overview of the institutional background of patent examination and its duration in China. The number of patent applications filed at the Chinese State Intellectual Property Office (SIPO) has grown tremendously in recent decades; by 2009, SIPO had become the world's third largest patent office. We find that the average grant lag in 1990–2002 was 4.71 years, with considerable variation across 30 different technology areas.

This paper provides a direct measure of the density of patent thickets based on patent citations. It describes the measurement approach and identifies technology areas especially affected by thickets.

Drawing on patent data for approximately 500 firms over 20 years, we advance recent theory on firm boundaries and test these propositions for the first time. We first provide evidence for the existence of knowledge complementarities between vertically related activities in a firm's value chain by showing that firms face increasing (decreasing) performance in conducting downstream activities (i.e., patent litigation) the less (more) they outsource related upstream activities (i.e., patent filing). We then propose and empirically demonstrate that vertical integration benefits through learning differ from vertical outsourcing costs through forgetting. We show that firms can partly offset these hidden outsourcing costs by sourcing similar upstream products from internal and external suppliers.

After developing a great product or process, it's important to protect it. This practitioner-oriented article discusses the strategic choice between using internal patent lawyers and outsourcing the task, drawing on research about the benefits and costs of different approaches to managing patent work.

It has been widely studied how organizational performance changes after the replacement of managers. However, there is little evidence whether environmental changes moderate the efficiency of management replacements. In this paper, I explicitly consider the effect of a change in the environment of organizations on post-replacement effects. Analyzing the performance effect of coach replacements in the German Soccer League before and after the introduction of the 3-points-rule theoretically and empirically I find that the magnitude of the performance effect of coach replacements differs under alternative regimes. The empirical analysis confirms predictions from my theoretical model and identifies moderating effects.

We examine the effect of patenting on the survival prospects of 356 Internet-related firms that made an initial public offering on the NASDAQ at the height of the stock market bubble of the late 1990s. By March 2005, almost 2/3 of these firms had delisted from the exchange. Changes in the legal environment in the US in the 1990s made it much easier to obtain patents on software, and ultimately, on business methods, though less than 1/2 of the firms in our sample obtained, or attempted to obtain, patents. For those that did, we hypothesize that patents conferred competitive advantages that translate into higher probability of survival, though they may also simply be a signal of firm quality.

We analyze the duration and outcomes of patent examination at the European Patent Office utilizing an unusually rich data set covering a random sample of 215,265 applications filed between 1982 and 1998. In our empirical analysis, we distinguish between three groups of determinants: applicant characteristics, indicators of patent quality and value, and determinants that affect the complexity of the examination task. The results from an accelerated failure time model indicate that more controversial claims lead to slower grants but faster withdrawals, whereas well-documented applications are approved faster and withdrawn more slowly. We find strong evidence that applicants accelerate grant proceedings for their most valuable patents, but that they also prolong the battle for such patents if a withdrawal or refusal is imminent.

There has been a wide-spread misconception based on the imprecise wording of Art. 52 of the European Patent Convention that the protection of business methods by patents is prohibited in Europe. This paper investigates the legal framework set by patent laws with respect to the patentability of business methods, contrasting the situation in Europe and the United States. It is shown that in practice business methods have never been excluded from patentability in Europe. The paper then provides empirical insights into the strategic use of business method patents based on patent applications in the franking device industry.

Recent studies of outlaw communities provide qualitative evidence of their existence and the organisation of the underlying innovation processes. We provide descriptive results from a large-scale survey of two online outlaw communities focussing on Microsoft's Xbox. In line with previous findings, we identify two types of participants in outlaw communities — user innovators and adopters. Based on 2,256 responses, we find that users modify their Xbox mainly to be able to increase the set of available functions. Users are also motivated to modify their Xbox for the sake of having fun and to conduct pirate behaviour. Finally, results from our survey suggest that user innovators are largely intrinsically motivated by fun and the intellectual stimulation of writing code for homebrew software.

This paper focuses on an extension of zero-inflated generalized Poisson (ZIGP) regression models for count data. We discuss generalized Poisson (GP) models where dispersion is modelled by an additional model parameter. Moreover, zero-inflated models, in which overdispersion is assumed to be caused by an excessive number of zeros, are discussed. In addition to ZIGP models considered by several authors, we now allow for regression on the overdispersion and zero-inflation parameters. Consequently, we propose tools for an exploratory data analysis on the dispersion and zero-inflation level. An application dealing with outsourcing of patent filing processes will be used to compare these nonnested models. The model parameters are fitted by maximum likelihood using our R package 'ZIGP' available on the Comprehensive R Archive Network (CRAN).

Previous econometric analyses of patent data rely on regression methods using purely parametric forms of the predictor for modeling the dependence of the response. These approaches lack the capability of identifying potential non-linear relationships between dependent and independent variables. In this paper, we present a Bayesian semiparametric approach making use of Markov Chain Monte Carlo (MCMC) simulation techniques which is able to capture these non-linearities. Using this methodology we reanalyze the determinants of patent oppositions in Europe for biotechnology/pharmaceutical and semiconductor/computer software patents. Our semiparametric specification clearly finds considerable non-linearities in the effect of various metrical covariates which has not been discussed previously. Further, a formal model validation based on ROC methodology which splits the data in a training and a validation data set shows a significant improvement of the explanatory and the predictive power of the semiparametric specification.