1,721,215 research outputs found
Semi-Nonparametric Estimation of Binary Choice Models Using Panel Data : an Application to the Innovative Activity of German Firms
No full textFrançois Laisney, Michael Lechner and Winfried Pohlmeier This paper presents an extension of Chamberlain's approach to modelling correlated random effects in a dichotomous model estimated on panel data. The extension consists in relaxing the arbitrary normality assumption made on all error terms and on specifying instead a SNP distribution for the composite error term resulting in each wave from Chamberlain's treatment of correlated random effects. An application to a panel of 1325 German firms illustrates the feasibility of the approach.
Utilisation jointe de données de panel et d'informations agrégées dans l'estimation d'un modèle Probit
No full textCombining Panel Data and Macro Information for the Estimation of a Panel Probit Model
by François Laisney and Michael Lechner
When studying particular subgroups of a population the econometrician typically has few observations, and should draw upon any additional relevant information. We illustrate, for the estimation of a labour-market participation model for lone mothers, the relative benefits derived from using the panel structure of the data in a GMM framework and from including macro information in the form of extra moments.Utilisation jointe de données de panel et d'informations agrégées dans l'estimation d'un modèle Probit
par François Laisney et Michael Lechner
Lors de l'étude de sous-populations particulières, l'économètre dispose souvent d'un nombre restreint d'observations, et la possibilité de recourir à des informations complémentaires prend une grande importance. À propos de l'estimation d'un modèle de participation de mères isolées au marché du travail, nous illustrons les gains d'efficacité obtenus dans le contexte de la méthode des moments généralisée par l'utilisation de la structure de panel des données et par l'inclusion, sous forme de moments supplémentaires, d'informations agrégées.Laisney François, Lechner Michael. Utilisation jointe de données de panel et d'informations agrégées dans l'estimation d'un modèle Probit. In: Économie & prévision, n°126, 1996-5. Analyse des comportements économiques à partir de données de panel, sous la direction de Pierre Blanchard et Patrick Sevestre. pp. 177-189
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Sensitivity of Matching-Based Program Evaluations to the Availability of Control Variables
Full text linkBased on new, exceptionally informative and large German linked employer-employee administrative data, we investigate the question whether the omission of important control variables in matching estimation leads to biased impact estimates of typical active labour market programs for the unemployed. Such biases would lead to false policy conclusions about the cost-effectiveness of these expensive policies. Using newly developed Empirical Monte Carlo Study methods, we find that besides standard personal characteristics, information on individual health and firm characteristics of the last employer are particularly important for selection correction. Moreover, it is important to account for past performance on the labour market in a very detailed and flexible way. Information on job search behaviour, timing of unemployment and program start, as well as detailed regional characteristics are also relevant.training, job search assistance, matching estimation, active labour market policies
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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