1,721,171 research outputs found
Skill Specific Unemployment with Imperfect Substitution of Skills
A large body of literature explains the inferior position of unskilled workers by imposing a structural shift in the labor force skill composition. This paper takes a different approach by emphasizing the connection between cyclical variations in skilled and unskilled labor markets. Using a stylized business cycle model with search frictions in the respective sub-markets, I find that imperfect substitution between skilled and unskilled labor creates a channel for the variations in the sub-markets. Together with a general labor augment- ing technology shock, it can generate downward sloping Beveridge curves. Calibrating the model to US data yields higher volatilities in the unskilled labor markets and reproduces stylized business cycle facts.business cycle, search frictions, skill specific unemployment, skill substitutability
Against All Odds? National Sentiment and Wagering on European Football
This paper studies how national sentiment in the form of either a perception or a loyalty bias of bettors may affect pricing patterns on national wagering markets for international sport events. We show theoretically that both biases can be profitably exploited by bookmakers by way of price adjustment (odds shading). The former bias induces bookmakers to shade odds against the domestic team, the latter to adjust them in a way that depends on the demand elasticity of bettors for their national favorite. Analyzing empirically a unique data set of betting quotas from online bookmakers in twelve European countries for qualification games to the UEFA Euro 2008, we find evidence for systematic biases in the pricing of own national teams in the odds for win offered across countries. Variations in the sign and magnitude of these deviations can be explained by differences across countries in the respective strengths of the perception and loyalty biases among domestic bettors.Football, Home Bias, Investment, Patriotism
Using R, LaTeX and Wiki for an Arabic e-learning platform
E-learning plays an important role in education as it supports online education via computer networks and provides educational services by utilising information technologies. We present a case study describing the development of an Arabic language elearning course in statistics. Discussed are issues concerning e-learning in Arab countries with special focus on problems of the application of e-learning in the Arab world and the difficulties concerning the design Arabic platforms such as language problems, cultural and technical problems, especially ArabTeX works difficulty with LaTeX format. Thus Wiki is offered as a solution to such problems. Wiki supports LaTeX and other statistical programs, for instance R, andWiki offers the solution to language problems. Details of this technology are discussed and a solution as to how this system can serve in building an Arab platform is presented.E-learning, MM*Stat, Wiki, ArabTeX, Statistical software
Dynamic Semiparametric Factor Models in Risk Neutral Density Estimation
Dimension reduction techniques for functional data analysis model and approximate smooth random functions by lower dimensional objects. In many applications the focus of interest lies not only in dimension reduction but also in the dynamic behaviour of the lower dimensional objects. The most prominent dimension reduction technique - functional principal components analysis - however, does not model time dependences embedded in functional data. In this paper we use dynamic semiparametric factor models (DSFM) to reduce dimensionality and analyse the dynamic structure of unknown random functions by means of inference based on their lower dimensional representation. We apply DSFM to estimate the dynamic structure of risk neutral densities implied by prices of option on the DAX stock index.dynamic factor models, dimension reduction, risk neutral density
Going Beyond Counting First Authors in Author Co-citation Analysis
The 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
JBendge: An Object-Oriented System for Solving, Estimating and Selecting Nonlinear Dynamic Models
We present an object-oriented software framework allowing to specify, solve, and estimate nonlinear dynamic general equilibrium (DSGE) models. The imple- mented solution methods for nding the unknown policy function are the standard linearization around the deterministic steady state, and a function iterator using a multivariate global Chebyshev polynomial approximation with the Smolyak op- erator to overcome the course of dimensionality. The operator is also useful for numerical integration and we use it for the integrals arising in rational expecta- tions and in nonlinear state space lters. The estimation step is done by a parallel Metropolis-Hastings (MH) algorithm, using a linear or nonlinear lter. Implemented are the Kalman, Extended Kalman, Particle, Smolyak Kalman, Smolyak Sum, and Smolyak Kalman Particle lters. The MH sampling step can be interactively moni- tored and controlled by sequence and statistics plots. The number of parallel threads can be adjusted to benet from multiprocessor environments. JBendge is based on the framework JStatCom, which provides a standardized ap- plication interface. All tasks are supported by an elaborate multi-threaded graphical user interface (GUI) with project management and data handling facilities.Dynamic Stochastic General Equilibrium (DSGE) Models, Bayesian Time Series Econometrics, Java, Software Development
Variations on the Author
“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
We 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
Teleworking and housing demand
Open Access via the Elsevier agreement We are grateful to the two anonymous referees and Gabriel Ahlfeldt (the editor) for their detailed comments and suggestions, which helped to improve the paper. We thank Tim Bolt, Luis Loría, Axel Werwatz and seminar participants at the AREUEA International Conference, the University of Aberdeen and the TU Berlin for helpful comments. We are grateful to the Centre of Real Estate Research and the Health Economics Research Unit of the University of Aberdeen for financial support that made the online survey possible. The usual disclaimer applies. Rainer Schulz: Conceptualisation, Methodology, Software, Validation, Formal analysis, Investigation, Writing. Verity Watson: Conceptualisation, Methodology, Software, Validation, Formal analysis, Investigation, Writing. Martin Wersing: Conceptualisation, Methodology, Software, Validation, Formal analysis, Investigation, Data curation, Writing.Peer reviewe
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