Penalized optimal designs for dose-finding

Optimal design under a cost constraint is considered, with a scalar coefficient setting the compromise between information and cost. It is shown that for suitable cost functions, by increasing the value of the coefficient one can force the support points of an optimal design measure to concentrate around points of minimum cost. An example of adaptive design in a dose-finding problem with a bivariate binary model is presented, showing the effectiveness of the approach.     

Modeling spatial learning in rats based on Morris water maze experiments

The Morris water maze, developed by Morris (J Neurosci Methods 1984: 11: 47–60), is a behavioral experiment designed to test the spatial memory. When repeating the experiment several times, the changes in time (latency) and distance (path) taken to reach the platform are indicators for the learning and memory abilities of the rat. In juvenile toxicity studies, it is of interest to test whether dosing juvenile rats with some compound of interest has an effect on its learning ability. The traditional analysis uses non‐parametric tests to check for a possible dose‐effect. However, due to the many tests performed, this approach lacks power. Here, an alternative method is proposed, accounting for the longitudinal design of the study, the right‐censoring of observations when animals did not find the platform and the correlation between the time and distance taken to reach the platform. Copyright © 2009 John Wiley & Sons, Ltd.     

A Comparison of Procedures for Controlling the False Discovery Rate in the Presence of Small Variance Genes: A Simulation Study

The Significance Analysis of Microarrays (SAM; Tusher et al., 2001 Tusher , V. G. , Tibshirani , R. , Chu , G. ( 2001 ). Significance analysis of microarrys applied to the ionizing radiation response . Proceedings of the National Academy of Sciences 98 : 5116 – 5121 .[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]) method is widely used in analyzing gene expression data while controlling the FDR by using resampling-based procedure in the microarray setting. One of the main components of the SAM procedure is the adjustment of the test statistic. The introduction of the fudge factor to the test statistic aims at deflating the large value of test statistics due to the small standard error of gene-expression. Lin et al. (2008 Lin , D. , Shkedy , Z. , Burzykowski , T. , Göhlmann , H. W. H. , De Bondt , A. , Perera , T. , Geerts , T. , Bijnens , L. ( 2008 ). Significance analysis of microarray (SAM) for comparisons of several treatments with one control . Biometric Journal, MCP 50 ( 5 ): 801 – 823 .[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]) pointed out that the fudge factor does not effectively improve the power and the control of the FDR as compared to the SAM procedure without the fudge factor in the presence of small variance genes. Motivated by the simulation results presented in Lin et al. (2008 Lin , D. , Shkedy , Z. , Burzykowski , T. , Göhlmann , H. W. H. , De Bondt , A. , Perera , T. , Geerts , T. , Bijnens , L. ( 2008 ). Significance analysis of microarray (SAM) for comparisons of several treatments with one control . Biometric Journal, MCP 50 ( 5 ): 801 – 823 .[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]), in this article, we extend our study to compare several methods for choosing the fudge factor in the modified t-type test statistics and use simulation studies to investigate the power and the control of the FDR of the considered methods.     

Using Capabilities as an Alternative Indicator for Well-being

This paper examines the potential of self-reported information on capabilities as an alternative indicator and aggregator for well-being. We survey a population of 18 year old first-year Bachelor students in applied economics and business studies and demonstrate a way in which capabilities can be measured on the level of life domains as well as on the general level of ‘life as a whole’. The data confirm the theoretical hypothesis that the set of capabilities is larger than the achieved functionings. We investigate and compare which variables influence general capabilities and satisfaction with life. We find that both concepts are equally depending on the ‘mood of the day’. On the other hand, we find some diverging influences that call for a debate on the (policy) relevance of different well-being concepts and their determining variables. The capabilities interpretation of well-being points to an important role of the parents (especially when they are divorced or rather strict) while the information on satisfaction is more related to personal and situational characteristics (such as not being single or the number of family visits).     

Dysfunctional Transactions and Therapeutic Functions: An Evolutive Model

The present study is a result of an interdisciplinary team's work, where a physicist, a family therapist and a developmental psychologist try to share their knowledge and epistemologies. In this kind of conflictual companionship, models of one discipline are tentatively applied to another. This doesn't imply that the different disciplines are isomorphic, but it provides for unusual frames of reference: questions, possibly essential ones, are reformulated in a new language, or in a perspective which was not accessible within the conceptual framework developed for one particular discipline. Our experience is that this kind of effort, in itself a provocative learning experience, is also conducive to original tentative answers in all disciplines involved. Be they of theoretical or experimental nature, it is then up to the specialists of these disciplines to validate the evolved propositions in terms of their own categories.     

Evaluation of job satisfaction in a sample of Spanish social workers through the ‘Job Satisfaction Survey’ scale

The objective of this study is to determine the level of job satisfaction experienced by social workers and to establish whether there are significant differences between the various levels of job satisfaction and a series of personal features and job characteristics. The participants were 947 social workers (861 women and 86 men) belonging to 35 of the 36 Professional Associations existing in Spain. The measurement tool used is the Job Satisfaction Survey scale, designed by Spector [2002. Psicología Industrial y Organizacional: Investigación y Práctica [Industrial and organizational psychology: Research and practice]. México: Manual Moderno]. The results show that the social workers surveyed experience moderate levels of job satisfaction (M?=?115.8; SD?=?21.4). The intrinsic factor that seems to have the greatest positive influence on job satisfaction is the nature of the job, while the extrinsic factors of pay, fringe benefits, and operating conditions are the ones that contribute most to job dissatisfaction, and social workers have no control over any of them.     

The Influence of Social Models on Retirement Savings: Evidence for European Countries

Population ageing, together with the negative effects of the recent economic and financial crisis that some European countries are still facing, have threatened the sustainability of public pension systems. In this context, voluntary private pensions have emerged as the most feasible alternative to supplement the minimum provided by Social Security Systems; however, this financial product does not enjoy its expected popularity. A potential explanation of this reality might be due to the fact that European countries are far from being homogeneous, nor their pensions systems. Therefore, any policy geared toward improving financial retirement planning should take into account these potential differences. As a first approach to their analysis, this paper proposes the existence of four different ‘social models’ in Europe -namely, Continental, Mediterranean, Nordic and Transitional-. Overall, empirical evidence confirmed the significant influence of country’ ‘social model’ on the decision to invest in retirement accounts on a sample of 31,468 individuals in 2013. It was also proved that this decision is positively related to age, household income and wealth, higher levels of formal education, job situation, good health status, and long-term planning horizons; and negatively related to age squared, household size or financial risk aversion. In short, future policies and reforms regarding private pensions should not only take into account the existence of individual differences among Europeans, but also the existence of differences depending on institutional and cultural country factors.     

Labor Mismatches: Effects on Wages and on Job Satisfaction in 17 OECD Countries

This study analyzes the effects of labor mismatches on wages and on job satisfaction in seventeen OECD countries by distinguishing between educational mismatch and skills mismatch. Using data from PIAAC, the results suggest that whereas educational mismatch shows greater effects on wages, the effects of labor mismatch on job satisfaction are generally better explained by skills mismatches. Both phenomena appear to be relevant for understanding the economic effects of labor mismatch and suggest that educational mismatch is not an accurate proxy for skills mismatch, mainly when the non-monetary effects of labor mismatch are addressed.     

OPTIMAL EMPLOYEE OWNERSHIP CONTRACTS UNDER AMBIGUITY AVERSION

The aim of this paper is to compute and describe the conditions of an optimal employee ownership contract between an employer and an ambiguity‐averse employee. We then introduce ambiguity aversion in the baseline model of Aubert et al. (2014) using the multiple prior preferences of Gilboa and Schmeidler (1989) and its extension proposed by Maccheroni et al. (2006). This model offers solutions that reconcile labor and financial economics and behavioral economics research findings on employee ownership. The paper focuses on the most common situation where employee ownership has a positive impact on corporate performance, but can also be used as an entrenchment mechanism. We determine the optimal company stock contribution, which corresponds to a perfect subgame Nash equilibrium in the ambiguity framework. Using the framework of Gilboa and Schmeidler (1989), we show that the optimal ownership contract is increasing with respect to the lower bound of the return expectation in the case of a high level of effort, and decreasing with respect to the upper bound of the return expectation in the case of a low level of effort. In the framework of Maccheroni et al. (2006), we prove that if aversion to ambiguity is sufficiently high, then we find the same behavior as in the case of no ambiguity. (JEL G11, G32, G34, J33)     

Factorial Validity of the Maslach Burnout Inventory-Human Services Survey (MBI-HSS) in a Sample of Spanish Social Workers

Burnout has been considered important to understanding the well-being of social workers and the quality of the services they render. Despite the ample international usage of the Maslach Burnout Inventory, its psychometric properties have come into question and alternative models of measuring the inventory have been suggested. The purpose of this study was to examine the psychometric properties and the applicability of a Spanish version of the Maslach Burnout Inventory-Human Services Survey (MBI-HSS) in an incidental sample of 947 social workers. Three alternative models of the MBI-HSS were tested for the purpose of identifying the most suitable model for measuring burnout in Spain. The confirmatory factor analysis supported the theory that the model of three correlated factors was superior to alternative models of one and two factors. The structure of three factors (emotional exhaustion, depersonalization, and personal accomplishment) and 19 items showed the best adjustment and a suitable internal consistency of the dimensions of the MBI-HSS. These findings demonstrate that the MBI-HSS has validity and reliability acceptable for measuring burnout in social workers, providing valuable information to the managers of social services in order to reduce burnout among social workers. The limitations of the study and recommendations for future investigation are emphasized.