Most existing reduced-form macroeconomic multivariate time series models employ elliptical disturbances, so that the forecast densities produced are symmetric. In this article, we use a copula model with asymmetric margins to produce forecast densities with the scope for severe departures from symmetry. Empirical and skew t distributions are employed for the margins, and a high-dimensional Gaussian copula is used to jointly capture cross-sectional and (multivariate) serial dependence. The copula parameter matrix is given by the correlation matrix of a latent stationary and Markov vector autoregression (VAR). We show that the likelihood can be evaluated efficiently using the unique partial correlations, and estimate the copula using Bayesian methods. We examine the forecasting performance of the model for four U.S. macroeconomic variables between 1975:Q1 and 2011:Q2 using quarterly real-time data. We find that the point and density forecasts from the copula model are competitive with those from a Bayesian VAR. During the recent recession the forecast densities exhibit substantial asymmetry, avoiding some of the pitfalls of the symmetric forecast densities from the Bayesian VAR. We show that the asymmetries in the predictive distributions of GDP growth and inflation are similar to those found in the probabilistic forecasts from the Survey of Professional Forecasters. Last, we find that unlike the linear VAR model, our fitted Gaussian copula models exhibit nonlinear dependencies between some macroeconomic variables. This article has online supplementary material. 相似文献
This article argues that social work in the UK needs to renegotiate its relationship with community welfare agencies. It begins by examining what we mean by local community and how welfare needs reflect complex non-linear dynamics unique to the local circumstances. It is argued that these are not always recognised in centralised policy agendas. The article broadly draws a parallel between policy issues for the European Community and for the national state. The drive for both is towards uniformity, which potentially fails to acknowledge the unique circumstances at both the national level between nations and the local level between communities.
The focus of the analysis is the lack of engagement with the subtleties of the local within the arena of social work education and practice. With the opportunity presented by the introduction of a new social work degree in the UK, the authors describe how a social work programme in Liverpool undertook a piece of research with the aim of creating an appropriate place for community welfare agencies in practice placements, the academic curriculum and, ultimately, with the next generation of social work practitioners. Eight welfare agencies within the proximity of Liverpool University, an area known as Toxteth, agreed to participate in the research to investigate what kind of placement module would enable local welfare agencies to engage meaningfully in the social work degree. Out of this process emerged a model for research based curriculum development involving local community agencies and academic institutions. More specifically for Liverpool, it placed the notion of social work's relationship with local community welfare at the heart of professional development for qualifying social workers, paving the way in this region of England for closer links between welfare agencies associated with civil society and professional social workers. 相似文献
What causes leaders to punish subordinates unjustly? And why might leaders keep punishing subordinates unjustly, even when this increases workplace misconduct? In the current paper we address these questions by suggesting that power and status cause leaders to punish unjustly. We review evidence on the effects of power and status on punishment, review how unjust punishments foster misconduct, and highlight how this creates a self-perpetuating feedback loop—leaders are more likely to punish in an unjust manner when subordinates engage in misconduct, but subordinates’ misconduct is partly caused by unjust punishments. We also discuss how leader-subordinate distrust may be at the heart of this phenomenon and how organizations may counteract unjust punishments. We draw attention to research areas that have received little attention and draw up an agenda for future research. Taken together, we integrate the literatures on power, status, punishment and trust, review evidence on when unjust punishments become perpetuating, challenge research suggesting that leaders are cautious when punishing, and guide future research on the topic of punishment in organizations. 相似文献
This study investigates the impact of service diversification on the rate and mode of firm growth in professional service firms (PSFs). Drawing on the extant PSF literature, we identify differing views regarding the growth impact of service diversification. Specifically, some scholars suggest that the external client benefits associated with service diversification should allow PSFs to expand revenues at a rapid pace and pursue less merger and acquisition activity, whereas others imply that increased diversification can cause internal challenges with respect to learning costs, coordination and innovation that can limit the rate of revenue growth and encourage more mergers and acquisitions. We test these competing views using longitudinal data on 137 accounting firms and cross-sectional data on 125 law firms and find that service diversification is negatively associated with the rate of firm revenue growth and positively associated with the use of mergers and acquisitions. 相似文献
There is no current validated clinical assessment tool to measure the attainment of midwifery student competence in the midwifery practice setting. The lack of a valid assessment tool has led to a proliferation of tools and inconsistency in assessment of, and feedback on student learning.
Objective
This research aimed to develop and validate a tool to assess competence of midwifery students in practice-based settings.
Design
A mixed-methods approach was used and the study implemented in two phases. Phase one involved the development of the AMSAT tool with qualitative feedback from midwifery academics, midwife assessors of students, and midwifery students. In phase two the newly developed AMSAT tool was piloted across a range of midwifery practice settings and ANOVA was used to compare scores across year levels, with feedback being obtained from assessors.
Findings
Analysis of 150 AMSAT forms indicate the AMSAT as: reliable (Cronbach alpha greater than 0.9); valid—data extraction loaded predominantly onto one factor; and sensitivity scores indicating level of proficiency increased across the three years. Feedback evaluation forms (n = 83) suggest acceptance of this tool for the purpose of both assessing and providing feedback on midwifery student’s practice performance and competence.
Conclusion
The AMSAT is a valid, reliable and acceptable midwifery assessment tool enables consistent assessment of midwifery student competence. This assists benchmarking across midwifery education programs. 相似文献