Thorsten Doherr

Genetic Algorithms: A Tool for Optimization in Econometrics - Basic Concept and an Example for Empirical Applications

This paper discusses a tool for optimization of econometric models based on genetic algorithms. First, we briefly describe the concept of this optimization technique. Then, we explain the design of a specifically developed algorithm and apply it to a difficult econometric problem, the semiparametric estimation of a censored regression model. We carry out some Monte Carlo simulations and compare the genetic algorithm with another technique, the iterative linear programming algorithm, to run the censored least absolute deviation estimator. It turns out that both algorithms lead to similar results in this case, but that the proposed method is computationally more stable than its competitor.

Individual Versus Institutional Ownership of University-Discovered Inventions

We examine how the ownership of intellectual property rights influences patenting of university-discovered inventions. In 2002, Germany transferred patent rights from faculty members to their universities. To identify the effect on the volume of patenting, we exploit the researcher-level exogeneity of the 2002 policy change using a novel researcher-level panel database that includes a control group not affected by the law change. For professors who had existing industry connections, the policy decreased patenting, but for those without prior industry connections, it increased patenting. Overall, fewer university inventions were patented following the shift from inventor to institutional ownership.

Inventor mobility and productivity in Italian regions

ABSTRACT This paper describes the interregional and international mobility of inventors in Italy and estimates its impact on total factor productivity (TFP) at the regional level for the period 1996–2011. A new database of mobile inventors is constructed and, using a set of geographically based instruments to address endogeneity, it shows that inventor in- and outflows affect regional TFP growth. Moreover, the positive effects of the inventors’ mobility (inflow) between different applicants take more time to materialize (relative to movements within the same company). Finally, the negative effects of inventor outflows are mainly driven by mobility between applicants.

Knowledge Creates Markets: The Influence of Entrepreneurial Support and Patent Rights on Academic Entrepreneurship

We use an exogenous change in German Federal law to examine how entrepreneurial support and the ownership of patent rights influence academic entrepreneurship. In 2002, the German Federal Government enacted a major reform called Knowledge Creates Markets that set up new infrastructure to facilitate university-industry technology transfer and shifted the ownership of patent rights from university researchers to their universities. Based on a novel researcher-level panel database that includes a control group not affected by the policy change, we find no evidence that the new infrastructure resulted in an increase in start-up companies by university researchers. The shift in patent rights may have strengthened the relationship between patents on university-discovered inventions and university start-ups; however, it substantially decreased the volume of patents with the largest decrease taking place in faculty-firm patenting relationships.

Inventor mobility index : a method to disambiguate inventor careers

Usually patent data does not contain any unique identifiers for the patenting assignees or the inventors, as the main tasks of patent authorities is the examination of applications and the administration of the patent documents as public contracts and not the support of the empirical analysis of their data. An inventor in a patent document is identified by his or her name. Depending on the patent authority the full address or parts of it may be included to further identify this inventor. The goal is to define an inventor mobility index that traces the career of an inventor as an individual with all the job switches and relocations approximated by the patents as potential milestones. The inventor name is the main criteria for this identifier. The inventor address information on the other hand is only of limited use for the definition of a mobility index. The name alone can work for exotic name variants, but for more common names the problem of namesakes gets in the way of identifying individuals. The solution discussed here consists in the construction of a relationship network between inventors with the same name. This network will be created by using all the other information available in the patent data. These could be simple connections like the same applicant or just the same home address, up to more complex connections that are created by the overlapping of colleagues and co-inventors, similar technology fields or shared citations. Traversal of these heuristically weighted networks by using methods of the graph theory leads to clusters representing a person. The applied methodology will give uncommon names a higher degree of freedom regarding the heuristic limitations than the more common names will get.

Mannheimer Innovationspanel (MIP), Scientific-Use-Files

Das ZEW erhebt seit 1993 jahrlich Daten zum Innovationsverhalten der deutschen Wirtschaft. Die Innovationserhebung deckt die Bereiche Bergbau, verarbeitendes Gewerbe, Energie, Baugewerbe, unternehmensnahe Dienstleistungen und distributive Dienstleistungen ab. Sie ist fur Deutschland reprasentativ und ermoglicht Hochrechnung fur die deutsche Wirtschaft insgesamt sowie fur einzelne Branchengruppen. Es wird im Auftrag des BMBF und in Kooperation mit infas und dem Fraunhofer-ISI durchgefuhrt. Das MIP ist gleichzeitig der deutsche Beitrag zu den Community Innovation Surveys (CIS) der Europaischen Kommission.