Application of Correspondence Analysis in the Assessment of Mine Tailings Dam Breakage Risk in the Mediterranean Region

A new statistical approach for preliminary risk evaluation of breakage in tailings dam is presented and illustrated by a case study regarding the Mediterranean region. The objective of the proposed method is to establish an empirical scale of risk, from which guidelines for prioritizing the collection of further specific information can be derived. The method relies on a historical database containing, in essence, two sets of qualitative data: the first set concerns the variables that are observable before the disaster (e.g., type and size of the dam, its location, and state of activity), and the second refers to the consequences of the disaster (e.g., failure type, sludge characteristics, fatalities categorization, and downstream range of damage). Based on a modified form of correspondence analysis, where the second set of attributes are projected as "supplementary variables" onto the axes provided by the eigenvalue decomposition of the matrix referring to the first set, a "qualitative regression" is performed, relating the variables to be predicted (contained in the second set) with the "predictors" (the observable variables). On the grounds of the previously derived relationship, the risk of breakage in a new case can be evaluated, given observable variables. The method was applied in a case study regarding a set of 13 test sites where the ranking of risk obtained was validated by expert knowledge. Once validated, the procedure was included in the final output of the e-EcoRisk UE project (A Regional Enterprise Network Decision-Support System for Environmental Risk and Disaster Management of Large-Scale Industrial Spills), allowing for a dynamic historical database updating and providing a prompt rough risk evaluation for a new case. The aim of this section of the global project is to provide a quantified context where failure cases occurred in the past for supporting analogue reasoning in preventing similar situations.     

The Rationality of Under‐employing the Best‐performing Soccer Players

Abstract. This paper analyses the influence of sport performance (productivity) and other variables measuring the economic contribution of soccer players, upon the coach's decision of selecting a particular player. Using as dependent variable the proportion of time that individuals play in the Spanish professional soccer league, the paper concludes that players' economic market value does significantly affect the coach's choice, revealing the existence of other aims different from maximizing sport performance. We also examine the type of discrimination associated with lower chances of playing, which leads to smaller earnings and poorer career opportunities. The empirical evidence does not support discrimination due to nationality.     

Convergence of the Guesstimation Algorithm

Economists attempting to build econometric or forecasting models are frequently restricted due to data scarcity in terms of short time series of data, and also of parameter non constancy and under-specification. In this case, a realistic alternative is often to guess rather than to estimate parameters of such models. An algorithm of repetitive guessing (drawing) parameters from iteratively changing distributions, with the objective of minimizing the squares of ex-post prediction errors, weighted by penalty weights and subject to a learning process, has been recently introduced. Despite obvious advantages, especially when applied for undersized empirical models with a large number of parameters, applications of Repetitive Stochastic Guesstimation have been, so far, limited. This has presumably been caused by the lack of rigorous proof of its convergence. Such proof for a class of linear models, both identifiable (in the economic sense) and not, is provided in this article.     

The macroeconomic impact of reforming a PAYG system: The Portuguese case

Abstract   The article analyses the impact of various types of reform options on social security pension system financial sustainability and on a range of macroeconomic variables. The HERPOR model is used to consider the likely effects of parametric reforms of the existing pay-as-you-go system, as well as those of a systemic reform. The article concludes that the former are sufficient to ensure financial sustainability, although they should be accompanied by employment implementation measures. The article concludes that a fully pre-funded system does not seem to be a viable option for policy-makers in the redesigning of social security pension systems, due to the high transition costs involved.     

Dialogic literary gatherings and out‐of‐home child care: Creation of new meanings through classic literature

Research on out‐of‐home child care has revealed that foster care programmes focused on educational attainment and reading have the potential to improve the academic outcomes of children in care. However, no studies have examined which elements of these programmes positively benefit children's emotional well‐being. This article presents evidence of the positive effects of implementing a successful educational action, dialogic literary gatherings, in a children's residential care institution. A qualitative study using a communicative‐oriented methodology was conducted and involved five participant observations and eight daily life stories with children in out‐of‐home care in Catalonia (Spain). The children's reflections demonstrated that reading classic books, such as Dickens' Oliver Twist, deeply influenced their feelings and self‐conceptions and created new and exciting meaning in their lives.     

Can alternative Taylor-rule specifications describe Federal Reserve policy decisions?

We look at how well several alternative Taylor-rule specifications describe Federal Reserve policy decisions in real time, using the newly developed Giacomini and Rossi (2007) test for non-nested model selection in the presence of (possible) parameter instability. Further, we isolate those Taylor-rule features that are most important for achieving relatively strong real-time performance. Key features of our preferred rule, which is robust to changing economic conditions, are the partial adjustment of the federal funds rate toward an equilibrium rate that depends on the unemployment rate and forward-looking inflation measures. We conclude by presenting an empirical application to show the policy relevance of our preferred rule in the context of the 2008–2009 recession.     

Do Mediterraneans really do it better? Explaining the lower gender wage gap in southern European countries

This article sets out to help provide a more detailed explanation for the narrower gender wage gap in Mediterranean countries. Two explanatory hypotheses are put forward and compared empirically using the European Union Statistics on Income and Living Conditions (EU‐SILC). The most widely accepted hypothesis is that gender wage gaps across countries are negatively correlated with gender employment gaps. The second hypothesis, however, is supported by evidence that the narrower wage gap in Mediterranean countries could be due to the differences in demand for labour in EU countries as a result ultimately of decisions by major corporations concerning the location of the activities in their value chain.     

Market Liberalisation,Vertical Integration and Price Behaviour in Tanzania's Coffee Auction

Whether market liberalisation can promote agricultural development in Africa depends on how well existing institutions can facilitate trade by private agents. This article assesses the performance of the Tanzania coffee marketing system after liberalisation and the emergence of private, vertically integrated exporters (VIEs). Increasing producer prices, declining marketing margins, and the continued provision of a useful auction for coffee that is delivered by traders who are not VIEs all suggest a degree of success for liberalisation. The presence of VIEs seems to have provided investment to reduce marketing costs, whilst a sufficient number of competing firms has limited non‐competitive behaviour in the market for coffee that is traded at the auction by non‐VIEs.     

Genetic variants in ATP6 and ND3 mitochondrial genes are not associated with aggressive prostate cancer in Mexican–Mestizo men with overweight or obesity

Mitochondrial defects have been related to obesity and prostate cancer. We investigated if Mexican–Mestizo men presenting this type of cancer, exhibited somatic mutations of ATP6 and/or ND3.Body mass index (BMI) was determined; the degree of prostate cancer aggressiveness was demarcated by the Gleason score. DNA from tumor tissue and from blood leukocytes was amplified by the polymerase chain reaction and ATP6 and ND3 were sequenced. We included 77 men: 20 had normal BMI, 38 were overweight and 19 had obesity; ages ranged from 52 to 83. After sequencing ATP6 and ND3, from DNA obtained from leukocytes and tumor tissue, we did not find any somatic mutations. All changes observed, in both genes, were polymorphisms. In ATP6 we identified, in six patients, two non-synonymous nucleotide changes and in ND3 we observed that twelve patients presented non-synonymous polymorphisms. To our knowledge, this constitutes the first report where the complete sequences of the ATP6 and ND3 have been analyzed in Mexican–Mestizo men with prostate cancer and diverse BMI. Our results differ with those reported in Caucasian populations, possibly due to ethnic differences.