An empirical comparison of two approaches for CDPCA in high-dimensional data

Statistical Methods & Applications - Modified principal component analysis techniques, specially those yielding sparse solutions, are attractive due to its usefulness for interpretation...     

Boom and bust: housing equity withdrawal and consumption decisions and their impacts on household wealth

The authors examine whether the surge in housing refinance and equity withdrawal generated by the housing boom disproportionately affected older households in terms of decisions on whether to refinance, whether to withdraw equity, and how much to withdraw, and how in turn these decisions affected their household wealth. Using the Federal Reserve's Survey of Consumer Finances, the authors found the highest rates of refinancing and cashing out equity among older (although not necessarily the oldest) households. The authors also found that appreciation in house value, being a baby boomer, and having higher household income were the factors that most increased the probability of refinancing and withdrawing equity. Amounts cashed out were higher among older than among younger households. Ordinary least squares (OLS) estimates showed that amounts withdrawn were increased by price appreciation, financial assets, and income, along with being a "pre-boomer" or "early boomer." Older cohorts displayed larger wealth effects than younger ones, but their withdrawn equity was a smaller percentage of total net worth. A relatively small percentage of respondents' dollars was used for consumption, and most dollars were used for home improvement, other investment, or debt repayment. However, massive equity withdrawal and the subsequent collapse of housing prices have caused housing leverage to soar, putting some homeowners "underwater" and jeopardizing others' retirement preparedness. The ensuing housing finance crisis raises numerous policy issues, from reform of mortgage underwriting, securitization, servicing, and foreclosure procedures, to potential limitations on borrowing against unrealized housing equity gains, to enhanced government transfers for distressed older homeowners, to local and state revenue policy changes.     

Designing the safety of healthcare. Participation of ergonomics to the design of cooperative systems in radiotherapy

This communication deals with the involvement of ergonomists in a research-action design process of a software platform in radiotherapy. The goal of the design project is to enhance patient safety by designing a workflow software that supports cooperation between professionals producing treatment in radiotherapy. The general framework of our approach is the ergonomics management of a design process, which is based in activity analysis and grounded in participatory design. Two fields are concerned by the present action: a design environment which is a participatory design process that involves software designers, caregivers as future users and ergonomists; and a reference real work setting in radiotherapy. Observations, semi-structured interviews and participatory workshops allow the characterization of activity in radiotherapy dealing with uses of cooperative tools, sources of variability and non-ruled strategies to manage the variability of the situations. This production of knowledge about work searches to enhance the articulation between technocentric and anthropocentric approaches, and helps in clarifying design requirements. An issue of this research-action is to develop a framework to define the parameters of the workflow tool, and the conditions of its deployment.     

The Structured Interview of Family Assessment Risk: Convergent Validity,Inter-rater Reliability and Structural Relations

The quality of parenting, composition and socio-economic status are family risk or protective factors on juvenile delinquency, however, there is not an instrument to help psychologists and social workers to specifically assess the adolescent offender’s family. This study set out to accomplish an additional validation study of the structured interview of family assessment risk (SIFAR), a structured professional judgment tool for the assessment of family risk and protective factors of juvenile delinquents. The statistical analyses included inter-rater reliability, convergent validity with YLS/CMI, the Partial Least Squares approach to structural equation modeling and receiving operator characteristics (ROC) analysis. A sample of 130 male adolescent delinquents detained in Portuguese forensic facilities and their parents, were paired analyzed. The YLS/CMI was used to analyze the convergent validity with SIFAR. SIFAR shows a strong correlation with the YLS/CMI family context, moderate to high values of inter-rater reliability; SIFAR factors show that they are predictive determinants of the Moderate Four risk factors. ROC analysis shows adequate accuracy power. The findings show that SIFAR it is useful as an additional assessment tool for structured risk assessment instruments since it allows understanding the vulnerabilities and strengths of the delinquent’s family.     

Personality and Subjective Well-Being: What Hides Behind Global Analyses?

The relation between personality and subjective well-being (SWB) remains involved in a considerable ambiguity and the numerous studies conducted have neglected an approach at a more detailed level of analysis. This study explores the idea that neuroticism, extraversion and conscientiousness facets predict differentially each SWB component. A battery of self-report questionnaires was used to assess personality and SWB in 398 teachers of primary and high schools. Findings of a cross-sectional study showed that neuroticism, extraversion and conscientiousness facets contributed to significantly explain the variance in positive affect, negative affect and life satisfaction. Moreover, these facets predicted differentially each of the three SWB components. At same time, this study corroborates two important premises: the specificity of facets as discrete traits and the independence of the three SWB components.     

Discriminant Analysis for the von Mises-Fisher Distribution

The von Mises-Fisher distribution is widely used for modeling directional data. In this article, we derive the discriminant rules based on this distribution to assign objects into pre-existing classes. We determine a distance between two von Mises-Fisher populations and we calculate estimates of the misclassification probabilities. We also analyze the behavior of the distance between two von Mises-Fisher populations and of the estimates of the misclassification probabilities when we modify the parameters of the populations or the samples size or the dimension of the sphere. Finally, we present an example with real spherical data available in the literature.     

Beyond products: new strategic imperatives for developing competencies in dynamic environments

Strategy research has often taken a product-centered perspective. When firms compete in environments characterized by accelerating product life cycles, mass customization, and technological discontinuities, a product-centered perspective on strategy may help explain a firm’s current competitive advantage. However, this perspective adds little guidance in making strategies that create competitive advantage in the future. In this paper, we present a perspective in which dynamic environments require firms to focus on (1) building market-driven, technological, and integration competencies, not a stream of product improvements, and (2) decoupling these competencies from current products in order to create and exploit new opportunities. We discuss the perspective of products as a temporary integration of market and technology trajectories. Research propositions are presented and future implications are discussed.     

Performance-based management and quality of work: an empirical assessment

In France, in the private sector as in the public sector, performance-based management tends to become a norm. Performance-based management is supposed to improve service quality, productivity and efficiency, transparency of allotted means and achieved results, and to better focus the activity of employees and of the whole organization. This text reports a study conducted for the French Ministry of Budget by a team of researchers in ergonomics, sociology and management science, in order to assess the impact of performance-based management on employees, on teams and on work organization. About 100 interviews were conducted with employees of all categories and 6 working groups were set up in order to discuss and validate or amend our first analyses. Results concern several aspects: workload and work intensification, indicators and performance management and the transformation of jobs induced by performance management.     

Maintenance of submersible pumps in the septic tanks: ergonomic and biological risks to the worker

In this study was observed the maintenance task of submersible pumps septic tanks installed in industrial bathrooms. This maintenance activity operators are exposed to various biological and ergonomic risks. This type of activity requires its great physical performers who are also subject to contact with human waste in the form of liquids, gases and solids. Besides the problems mentioned, are still exposed to high temperatures that can cause diseases such as hyperthermia or heatstroke. These aspects were observed using the ergonomic assessment methodology in order to suggest improvements that are reflected in productivity and employee satisfaction.