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. --Genetic Algorithm,Semiparametrics,Monte Carlo Simulation

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

Applied Information Technology opens Virtual Platform for the Legacy of Alexander von Humboldt

The Humboldt Digital Library (HDL) is a project that aims to provide digital access to the legacy of Alexander von Humboldt. The HDL runs on an open source library developed in the Hochschule Offenburg and provides a virtual research environment in which researchers can work more effectively. This article presents the development made in the HDL to provide alternative ways of content dissemination through the OAI protocol.Through the implemtantion of the OAI-PMH data provider in the HDL, the library is accessibly in many universities and research centers everywhere around the globe

Geothermie kompakt – online lernen

Die geothermischen Energieressourcen im Oberrheingebiet rücken immer mehr in den Brennpunkt für eine nachhaltige Energieversorgung. Um die Grundlagen und Potenziale dieser Energiequelle darzustellen, wurde ein E-Learning-Seminar „Geothermie kompakt – online lernen“ entwickelt, das erstmalig im Rahmen der Messe GeoTHERM 2008 in Offenburg als „Virtuelles Klassenzimmer“ präsentiert wurde. Die Inhalte des Kurses und das Lernmaterial wurden in kooperativer Zusammenarbeit der Autoren nach wissenschaftlichen Methoden und pädagogischen Erkenntnissen zum E-Learning erarbeitet. Der Moodle- Kurs thematisiert die Grundlagen der Geothermie, wobei speziell auf Fragen nach der Art der geothermischen Ressourcen und deren Nutzungsmöglichkeiten eingegangen wird. Die Kursmodule wurden so konzipiert, dass sie als Lehrmaterial für Lehrende wie Lernende verwendbar sind

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

Humboldt digital library and interconnectedness

This is the author's accepted manuscript. The original publication is available at www.springerlink.com.The Humboldt digital library (HDL) represents an innovative system to access the works and legacy of Alexander von Humboldt in a digital form on the Internet (www.avhumboldt.net). It contributes to the key question about how to present interconnected data in an appropriate form using information technologies. The HDL has been created as a dynamic digital library with the capability of connecting multilingual and multimedia data from diverse online archives. Humboldt’s volumes have become available, but beyond that any relevant information related to the observations of Humboldt, even outside the works can become immediately accessible. This makes it possible to recognize natural changes and compare Humboldt’s descriptions with recent situations. The technology we have developed addresses the issues of sustainability and makes it possible to detect changes in the environment since the time of Humboldt’s observations

Exploring the Americas in a Humboldt Digital Library: Problems and Solutions

This is the author's accepted manuscript. The published version is available from http://www.amergeog.org/gr/jul06/baron.html

Counterfactual impact evaluation of cohesion policy. Work package 2: Examples from support to innovation and research. Final report

The goal of this project was twofold. The first objective was to find out to what extent publicly available beneficiary data (from managing authorities and commercial databases) could be used for quantitative, econometric counterfactual analysis. This led to a second objective: in the countries and regions where data was most promising, a treatment effects analysis of the impacts of Cohesion Policy on innovation activities at the firm level has been conducted

Disambiguation of Researcher Careers: Shifting the Perspective from Documents to Authors

The thesis describes an algorithm that disambiguates the namespaces of inventors and researchers, spawned by their patents and publications, into career paths. A probabilistic theory to assess the risk of erroneously linking documents of namesakes, different individuals with a mutual name, into one career bypasses the need for training datasets, thereby avoiding a namesake bias caused by the inherent underestimation of namesakes in training/benchmark data. The economic relevance of identified careers is illustrated by two applications. The first one outlines the impact of inter-regional inventor mobility in Italy on the total factor productivity of the sending and receiving regions. We show that an inflow of high skilled labor has a significant positive effect on TFP, while outflow decreases it. We further separate mobility in firm-internal relocation and job switches to find a more pronounced effect for the latter mobility. The second application observes the reaction of German university researchers to an exogenous change in federal law pertaining the property rights of their inventions equivalent to the Bayh Dole Act. Being able to trace their careers along with the careers of an unaffected control group allows us to evaluate the efficacy of technology transfer offices replacing the former informal activities of the university professors in regard of academic entrepreneurship. We find that an overall decrease of university patenting neutralizes any institutionalized efforts of spurring entrepreneurship at the expense of informal faculty-firm networks as channels for knowledge transfer

The SearchEngine: A holistic approach to matching

The SearchEngine is an open source project providing an integrated framework for diverse matching activities, especially the linkage of large scale firm data by fuzzy criteria like company names and addresses. At its core, it utilizes an efficient candidate retrieval mechanism implementing a word respectively token driven heuristic. Every record in one table becomes a search term to retrieve similar candidate records in the base table according to a search strategy replacing blocking strategies of conventional matching efforts. Because similarity is inherently established by the candidate selection, it is only required to filter false positives by using the meta data export file derived from the matching heuristic to implement a machine learning approach. This paper discusses the general foundation of the heuristic and the algorithm while two detailed walkthroughs of company linkages show practical example