Work Sharing and Productivity : Evidence from a Natural Experiment

This paper is the first to examine empirically how work sharing influences workers' productivity, using a unique data set from a large Canadian firm. This firm has adopted a work sharing scheme for one year, which allows us to introduce a natural experiment approach of comparing workers' productivity before and after the implementation of work sharing. We find that work sharing has led to a significant decrease in labor productivity. Cet article examine empiriquement l'impact du partage du travail sur la productivité des travailleurs d'une grande firme canadienne. L'application de la semaine réduite de travail pendant un an au sein de cette entreprise nous permet de comparer analytiquement la productivité des employés avant et après l'adoption de ce programme. Nos résultats révèlent que l'expérimentation de la semaine réduite de travail provoque une baisse significative de la productivité des travailleurs.Productivity, Work Sharing, Work Organisation Methods, Productivité, partage du travail, modes d'organisation du travail

A study of the relationship between WISC and school success of emotionally disturbed children

Since the publishing of the Wechsler Intelligence Scale for Children in 1949, the majority of the validation don procedures have been correlations of the WISC with other intelligence teats or with achievement tests. As Littell (1960) indicated in his review of the research, both methods have yielded high correlations and are responsible in part for the wide acceptance of the WISC. While research has well established the ability of the WISC and other intelligence teats to predict school achievement in a normal population, the generalization of these findings to a population of emotionally disturbed children is in question for several reasons which will be discussed

Analyse de l'impact productif des pratiques de rémunération incitative pour une entreprise de services : Application à une coopérative financière québécoise

We measure the effect of profit-sharing incentive schemes on productivity in the banking sector. We use data collected from the payroll records of different (and autonomous) branches of a Québec financial cooperative. Beginning in 1994, some of these branches introduced profit-sharing compensation systems. We estimate a production function for this institution, allowing for the presence of profit-sharing. Our results suggest that branches with profit-sharing had 10% higher productivity than those without. Not all of this increase can be attributed to profit-sharing, however, since we lack information on the presence of other human-resource practices that were introduced into these firms. L'objectif principal de cet article est de mesurer l'impact des systèmes de rémunération incitative sur la productivité d'une entreprise de services, en tenant compte de la possibilité de biais de sélection qui survient lorsque la décision d'implanter de telles pratiques n'est pas aléatoire. Les données que nous avons utilisées proviennent d'une coopérative financière québécoise. Nous les avons utilisées pour estimer une fonction de production basée sur une mesure originale et univariée de la production. Nous trouvons un impact significatif de près de 10 %. Cette mesure est légèrement supérieure à ce qui est observé dans la litérature en général. Elle ne peut cependant être entièrement attribuée aux intéressements en raison de l'absence d'information sur la présence d'autres pratiques de gestion des ressources humaines (PGRH) pouvant influencer la productivité.Banks, credit unions, productivity, profit-sharing, Banques, productivité, intéressements, coopératives financières

Investigation of Dimensions of Social-Emotional Classroom Behavior and School Readiness for Low-Income Urban Preschool Children

The present study identified higher-order relationships among teacher assessments of approaches to learning and emotional and behavioral adjustment constructs for urban, low-income preschool children. It examined the unique contribution of these dimensions to cognitive and social competencies and risk of poor academic outcomes. Analyses of a large, representative sample of urban Head Start children revealed two distinct and reliable, higher-order dimensions of classroom adjustment behavior: Regulated and Academically Disengaged Behavior. Both of the dimensions contributed unique variance to the prediction of early mathematics ability and general classroom competencies prior to kindergarten entry, controlling for child demographics. Each dimension also contributed independently to the prediction of academic risk, controlling for child demographics. Implications for practice and policy were discussed

Separable Inverse Problems, Blind Deconvolution, and Stray Light Correction for Extreme Ultraviolet Solar Images.

The determination of the inputs to a system given noisy output data is known as an inverse problem. When the system is a linear transformation involving unknown side parameters, the problem is called separable. A quintessential separable inverse problem is blind deconvolution: given a blurry image one must determine the sharp image and point spread function (PSF) that were convolved together to form it. This thesis describes a novel optimization approach for general separable inverse problems, a new blind deconvolution method for images corrupted by camera shake, and the first stray light correction for extreme ultraviolet (EUV) solar images from the EUVI/STEREO instruments. We present a generalization of variable elimination methods for separable inverse problems beyond least squares. Existing variable elimination methods require an explicit formula for the optimal value of the linear variables, so they cannot be used in problems with Poisson likelihoods, bound constraints, or other important departures from least squares. To address this limitation, we propose a generalization of variable elimination in which standard optimization methods are modified to behave as though a variable has been eliminated. Computational experiments indicate that this approach can have significant speed and robustness advantages. A new incremental sparse approximation method is proposed for blind deconvolution of images corrupted by camera shake. Unlike current state-of-the-art variational Bayes methods, it is based on simple alternating projected gradient optimization. In experiments on a standard test set, our method is faster than the state-of-the-art and competitive in deblurring performance. Stray light PSFs are determined for the two EUVI instruments, EUVI-A and B, aboard the STEREO mission. The PSFs are modeled using semi-empirical parametric formulas, and their parameters are determined by semiblind deconvolution of EUVI images. The EUVI-B PSFs were determined from lunar transit data, exploiting the fact that the Moon is not a significant EUV source. The EUVI-A PSFs were determined by analysis of simultaneous A/B observations from December 2006, when the instruments had nearly identical lines of sight to the Sun. We provide the first estimates of systematic error in EUV deconvolved images.PHDApplied and Interdisciplinary MathematicsUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/99797/1/shearerp_1.pd