Identities, conflicting behavioural norms and the importance of job attributes

The paper empirically expounds the richness of the identity approach to labour-market behaviour by allowing individuals to experience identity conflict. Specifically, it investigates the relationship between the importance individuals attach to labour-market activities - which is influenced by the identity to which they adhere - and their preferences for job attributes. The analysis shows that individuals who consider labour-market success as instrumental for achieving their life goals tend to attach importance to job characteristics such as pay level and career and training opportunities. Individuals for whom non-labour-market activities are important and in conflict with labour-market activities are found to attach importance to the possibility of working on a convenient time schedule. Moreover, consistently with the identity approach to labour-market behaviour, men appear to resolve the conflict between career and non-work activities in favor of the former.Finally, unobserved factors that increase the desire to work part-time have a negative impact on the likelihood of attaching importance to the training and career opportunities offered by the job.     

A geometric approach to transdimensional markov chain monte carlo

The authors present theoretical results that show how one can simulate a mixture distribution whose components live in subspaces of different dimension by reformulating the problem in such a way that observations may be drawn from an auxiliary continuous distribution on the largest subspace and then transformed in an appropriate fashion. Motivated by the importance of enlarging the set of available Markov chain Monte Carlo (MCMC) techniques, the authors show how their results can be fruitfully employed in problems such as model selection (or averaging) of nested models, or regeneration of Markov chains for evaluating standard deviations of estimated expectations derived from MCMC simulations.     

Over-relaxation methods and coupled Markov chains for Monte Carlo simulation

This paper is concerned with improving the performance of certain Markov chain algorithms for Monte Carlo simulation. We propose a new algorithm for simulating from multivariate Gaussian densities. This algorithm combines ideas from coupled Markov chain methods and from an existing algorithm based only on over-relaxation. The rate of convergence of the proposed and existing algorithms can be measured in terms of the square of the spectral radius of certain matrices. We present examples in which the proposed algorithm converges faster than the existing algorithm and the Gibbs sampler. We also derive an expression for the asymptotic variance of any linear combination of the variables simulated by the proposed algorithm. We outline how the proposed algorithm can be extended to non-Gaussian densities.     

Poisson and negative binomial dynamics for counted data under CUSUM-type charts

Control charts for counted data are commonly designed assuming that counts follow Poisson dynamics. However, in various real situations, the true underlying dynamics of the events are more properly modelled by a negative binomial process. This paper examines the consequences of the Poisson approximation to negative binomial dynamics for counts under CUSUM-type schemes. It is essentially found that, on setting up Poisson dyamics for an underlying negative binomial data structure, the real in-control average run length decreases, whereas the sensitivity of the chart is affected less. These results warn against the routine use of the Poisson assumption in planning control charts for counts.     

Foreign Direct Investment,Trade, and Skilled Labour Demand in Eastern Europe

In this paper, we study the effects of inward foreign direct investment (FDI) and trade on relative skilled labour demand in Poland, Hungary, and the Czech Republic. Our estimates show significant heterogeneity in the FDI effect across the three economies: the effect is always significantly positive for Hungary, weakly negative for Poland, and negligible for the Czech Republic. As to trade, we find much more homogeneity in coefficient estimates, which are generally negative for all countries, although significant only in the case of Hungary.     

Psychophysical conditions and hormonal secretion in nurses on a rapidly rotating shift schedule and exposed to bright light during night work

Abstract

The psychophysical conditions of 15 young female nurses, working in a rapidly-rotating shift system (2-2-2-2), modified according to some psychophysiological criteria, and exposed to short period (4 × 20 min) of bright light (2350 Lux) during their night duty, were studied in order to evaluate their adaptation to night work and to test a possible positive effect on it of bright light. Subjective evaluations of work load and psychophysical conditions, performance measures, hormonal excretion (cortisol, 6-sulphatoxymelatonin and catecholamines), oral temperature and activity-sleep logs were taken during the shiftwork cycle, comprising one morning, one afternoon and two consecutive nights under normal and bright light. The results showed that this rapidly-rotating shift system had little effect upon the normal circadian rhythms of the body. Moreover, the lengthening of the night shift to 10 h can be considered to be acceptable, provided that work load is reduced and there are sufficient rest pauses available. On the other hand, the reduction to 7 h of the length of the day shifts and delayed start of the morning shift to 07:00 h appeared to be convenient both in relation to the work load and sleep duration. Some positive effects of bright light upon psychophysical conditions and performance efficiency were noted, while hormonal excretion and body temperature did not show any effect of bright light; in particular, melatonin excretion was not suppressed appreciably by the bright light used.     

The scorpions of the urban habitat of Rome (Italy)

A review of the scorpions (three species of the genus Euscorpius, family Chactidae) found in the urban habitat of Rome, Central Italy, together with an analysis of the factors which affect their distribution and abundance in the town, is pointed out. It appears that Euscorpius carpathicus, a species commonly found on limestone terrains in Latium, is frequent, though not particularly abundant, in the urban area of the city especially along the course of the Tiber River. It appears that Euscorpius flavicaudis, a species commonly found on volcanic terrains in Latium and the most common terrains in and around the area of Rome, is the most common species in both the urban and suburban areas of the city. It appears that Euscorpius italicus, a species common in north and northeastern Latium, is represented, in the sample of the scorpions of the city, by a single, possibly aberrant, specimen.     

Bivariate Semi-Markov Process for Counterparty Credit Risk

We consider the problem of constructing an appropriate multivariate model to study counterparty credit risk in the credit rating migration problem. For this financial problem different multivariate Markov chain models were proposed. However, the Markovian assumption may be inappropriate for the study of the dynamics of credit ratings, which typically show non Markovian-like behavior. In this article, we develop a semi-Markov approach to study the counterparty credit risk by defining a new multivariate semi-Markov chain model. Methods are given for computing the transition probabilities, reliability functions and the price of a risky Credit Default Swap.