Using conditional independence for parsimonious model-based Gaussian clustering

In the framework of model-based cluster analysis, finite mixtures of Gaussian components represent an important class of statistical models widely employed for dealing with quantitative variables. Within this class, we propose novel models in which constraints on the component-specific variance matrices allow us to define Gaussian parsimonious clustering models. Specifically, the proposed models are obtained by assuming that the variables can be partitioned into groups resulting to be conditionally independent within components, thus producing component-specific variance matrices with a block diagonal structure. This approach allows us to extend the methods for model-based cluster analysis and to make them more flexible and versatile. In this paper, Gaussian mixture models are studied under the above mentioned assumption. Identifiability conditions are proved and the model parameters are estimated through the maximum likelihood method by using the Expectation-Maximization algorithm. The Bayesian information criterion is proposed for selecting the partition of the variables into conditionally independent groups. The consistency of the use of this criterion is proved under regularity conditions. In order to examine and compare models with different partitions of the set of variables a hierarchical algorithm is suggested. A wide class of parsimonious Gaussian models is also presented by parameterizing the component-variance matrices according to their spectral decomposition. The effectiveness and usefulness of the proposed methodology are illustrated with two examples based on real datasets.     

Employers' attitudes towards long‐term unemployed people and the role of activation in Switzerland

Over the last few years, most OECD countries have extended their activation policy to new groups of non‐working people, including the long‐term unemployed (LTU). However, it is widely known that employers tend to regard LTU people as potentially problematic persons. This is likely to constitute a major obstacle for long‐term unemployed jobseekers. On the basis of a survey among employers in a Swiss canton (N = 722), this article aims to shed light on the perception employers have of the long‐term unemployed and whether this may matter for their recruitment practices. It also asks what, from the employer point of view, may facilitate access to employment for an LTU person. A key finding is that large companies have a worse image of the long‐term unemployed and are less likely to hire them. Furthermore, independent of company size, a test period or the recommendation of a trustworthy person is seen as the factors most likely to facilitate access to jobs for LTU people.     

Large Deviation Principles for Sequences of Maxima and Minima

In this article, we consider sequences of i.i.d. random variables and, under suitable conditions on the (common) distribution function, we prove large deviation principles for sequences of maxima, minima and pairs formed by maxima and minima. The i.i.d. random variables can be either unbounded or bounded; in the first case maxima and minima have to be suitably normalized.     

Measuring Health Inequality in US: A Composite Index Approach

Social Indicators Research - In this paper, we use the standardized mortality rates for 21 mutual exclusive causes of death to propose a composite index of US county-level health performances in...     

FAMILY TIES AND POLITICAL PARTICIPATION

We establish an inverse relationship between family ties and political participation, such that the more individuals rely on the family as a provider of services, insurance, and transfer of resources, the lower is one's civic engagement and political participation. We also show that strong family ties appear to be a substitute for generalized trust, rather than a complement to it. These three constructs—civic engagement, political participation, and trust—are part of what is known as social capital; therefore, in this paper, we contribute to the investigation of the origin and evolution of social capital. We establish these results using within‐country evidence and looking at the behavior of immigrants from various countries in 32 different destination places.     

Brazil and the Shifting Consensus on Development Co‐operation: Salutary Diversions from the ‘Aid‐effectiveness’ Trail?

Emerging economies emphasise horizontality and mutual opportunity in their relationship with developing countries, promising an alternative to the failings of traditional North‐South co‐operation. This article draws on research on Brazil's technical co‐operation and its health dimension to compare the Brazilian model with established aid‐effectiveness' principles and to discuss the appropriateness of the latter as standards against which to appraise emerging donors' co‐operation. The analysis shows that, despite progress towards greater dialogue between traditional and emerging donors, the ‘aid‐effectiveness’ framework still falls short of capturing the idiosyncrasies of South‐South co‐operation and therefore offers an incomplete international standard on how best to conduct development co‐operation.     

Lean practices and their effect on performance: a literature review

This paper introduces a literature review of 83 studies dealing with the degree of adoption of lean manufacturing practices around the world, and the links between those practices and organisation performance. The results of this study revealed that lean practices application still occurs in a fragmented way, disregarding the systemic linkage that is essential to lean manufacturing. Forty-one articles have suggested a positive effect of lean practices in at least one operational, financial and/or environmental performance metric. Nevertheless, five studies indicated that some lean practices had a negative effect on operational or financial performance. High demand variability, a perceived result of long-term lean manufacturing implementation, a country/company’s organisational culture and the difficulty of traditional costing production systems to measure and compare investments and economic gains from adopting lean manufacturing over time are some of the reasons to explain that negative effect of lean practice on performance.     

A Recast Framework for Welfare Deservingness Perceptions

Social Indicators Research - Many important societal debates revolve around questions of deservingness, especially when it comes to debates related to inequality and social protection. It is...