On robust causality nonresponse testing in duration studies under the Cox model

High survey nonresponse in unemployment duration studies may have a strong effect on inference if the so called causal mechanism is present. A robust method of testing the causal nonresponse is proposed for data sets where survey information can be combined with complete administrative records. It is assumed that population distribution follows approximately the Cox regression model. Formal justification of the method and a comparative simulation study are included.     

Affective and Cognitive Factors Influencing Sensitivity to Probabilistic Information

In study 1 different groups of female students were randomly assigned to one of four probabilistic information formats. Five different levels of probability of a genetic disease in an unborn child were presented to participants (within‐subject factor). After the presentation of the probability level, participants were requested to indicate the acceptable level of pain they would tolerate to avoid the disease (in their unborn child), their subjective evaluation of the disease risk, and their subjective evaluation of being worried by this risk. The results of study 1 confirmed the hypothesis that an experience‐based probability format decreases the subjective sense of worry about the disease, thus, presumably, weakening the tendency to overrate the probability of rare events. Study 2 showed that for the emotionally laden stimuli, the experience‐based probability format resulted in higher sensitivity to probability variations than other formats of probabilistic information. These advantages of the experience‐based probability format are interpreted in terms of two systems of information processing: the rational deliberative versus the affective experiential and the principle of stimulus‐response compatibility.     

When Does Information about Probability Count in Choices Under Risk?

The question addressed in the present research is whether in naturalistic risky decision environments people are sensitive to information about the probability parameter. In Study 1, we showed that in naturalistic scenarios participants generally revealed little interest in obtaining information about the outcomes and probabilities. Moreover, participants asked fewer questions about probabilities for scenarios containing moral considerations. In Study 2, it was shown that, when supplied with information on probabilities, people could be sensitive to this information. This sensitivity depends on two factors. People were less sensitive to probabilities in scenarios perceived as containing ethical considerations. People were also less sensitive to probabilities when they were faced with a single-choice situation than when they were faced with a series of lotteries with different probabilities. This can be accounted for in terms of the evaluability principle.     

Robust estimation in the generalized poisson model

A computationally simple method of robust estimation in the generalized Poisson model is presented. Estimators are proved to be optimal in the sense of local minimax testing, conditionally on the explanatory variable. Results of a Monte Carlo experiment are supplemented where robust and efficient estimators are compared.     

Selection of resilient supply portfolio under disruption risks

This paper deals with the optimal selection and protection of part suppliers and order quantity allocation in a supply chain with disruption risks. The protection decisions include the selection of suppliers to be protected against disruptions and the allocation of emergency inventory of parts to be pre-positioned at the protected suppliers. The decision maker needs to decide which supplier to select for parts delivery and how to allocate orders quantity among the selected suppliers, and which of the selected suppliers to protect against disruptions and how to allocate emergency inventory among the protected suppliers. The problem objective is to achieve a minimum cost of suppliers protection, emergency inventory pre-positioning, parts ordering, purchasing, transportation and shortage and to mitigate the impact of disruption risks by minimizing the potential worst-case cost. As a result a resilient supply portfolio is identified with protected suppliers capable of supplying parts in the face of disruption events. A mixed integer programming approach is proposed to determine risk-neutral, risk-averse or mean-risk supply portfolios, with conditional value-at-risk applied to control the risk of worst-case cost. Numerical examples are presented and some computational results are reported.     

Perception and Acceptance of Technological and Environmental Risks: Why Are Poor Countries Less Concerned?

The research has been aimed at answering two questions: (1) What factors impact perception and acceptance of technological and environmental hazards? (2) Why are rich societies involved more in protecting their environment and health than poor societies? Data has been collected from representative samples of two countries—Poland and Sweden. The results indicate that (1) contrary to earlier findings, the inverse relations between perceived benefits and dangers of hazards has not been observed, (2) acceptance of a risk has been mostly influenced by perceived benefits, (3) rejection of a risk has been mostly influenced by its perceived harmful consequences. Concerning the second question, it has been found that: (1) perceived hazard's danger and benefit is not the only factor that impacts its acceptance, and (2) a broader economic context can impact acceptance (tolerance) of hazards. It has been found that being aware of high dangers and not very high benefits of hazardous activities, Poles still have accepted them. Thus, Poles seem to follow an old proverb: “When one does not have what one likes, one has to like what one has.”     

Interactive effect of individual factors on nurses' health and sleep

Abstract

There is a tendency in studies concerning individual diferences in shiftwork tolerance to analyse the moderating effect of individual factors separately as if they acted independently. The aim of this study was to examine the interactive effect of individual factors (i.e. morningness, flexibility, languidity, neuroticism, extroversion) on nurses' health and sleep. A hundred female nurses (mean age 25.9 years, SD = 3.7 years) working a 2 × 12-h shift system were chosen from a larger study conducted among Intensive Care Unit staff. All subjects completed the Standard Shiftwork Index. Multiple regression analyses show that interactions of neuroticism and other factors (languidity, morningness) predict the majority of health and sleep complaints rather than neuroticism itself. Correlation analyses revealed that the interaction of neuroticism and languidity correlates higher with some indices of impaired health and sleep disturbances than when these factors are taken separately. The contribution of flexibility together with extroversion in interactions with neuroticism, and with neuroticism and languidity weaken the relations of languidity and neuroticism with health and sleep indices. The results show that some individual features tend to strengthen or counteract one another in relation to symptoms of shiftwork intolerance.     

Das polnische Familienrecht im Reformprozeß der staatlichen Ordnung

In view of the political reform in Poland, the ratification of international conventions and Poland’s intention of joining the European Union, a revision of both civil law and family law, which has been codified separately hitherto, is required. The author analyses the proposals made by the commission for the codification of the civil law and presents further possibilities for a solution.As far as the family law reform is concerned, optional civil marriage has been introduced. The same law lays down that a marriage is void in the case of an error regarding the partner and the event that the marriage was concluded under threat. Whereas the principle of irretrievable marriage breakdown remains unchanged, the introduction of divorce on request of one partner without judicial control has been refused. Furthermore, the legal separation is to be introduced.According to the author, the main emphasis of the reformatory efforts is being placed on the matrimonial property law. He reports on the commission’s proposal on the introduction of the community of surplus as a new matrimonial property regime, the introduction of a matrimonial property register and the extension of the spouses’ rights to settle their marital property rights by contract.With regard to the parent and child law the author analyses the impications of new assisted reproduction technologies for the right to challenge paternity and questions of maintenance.Finally the author refers to the status of the child in the new constitution and points out the necessity of hearing the children in the course of divorce proceedings.     

An integer programming approach to scheduling in a contaminated area

This paper presents a time-indexed integer programming formulation for scheduling dependent jobs executed by a team of workers in an area contaminated with radio-active or chemical materials. The dynamics of the harmful factor and the norms of organism recovery imply that each work period for a job should be immediately followed by a rest period for the worker executing this job and the length of the rest period depends on the start time of the corresponding work period. The problem is modeled as an NP-hard problem of scheduling on unrelated parallel processors with start time dependent processing times and different objective functions: maximum or total completion time and maximum or total tardiness. The special case of scheduling jobs executed by a single worker is also considered. Numerical examples and some computational results are reported.     

Intermediate efficiency by shifting alternatives and evaluation of power

We study a modification of the notion of asymptotic intermediate efficiency of statistical tests by defining it in terms of shifting alternatives. We prove a theorem providing conditions for its existence and show that this modification is closely related to the original Kallenberg's asymptotic intermediate efficiency in a quite general setting. Next, we find estimates for differences between powers of the Neyman–Pearson test under original alternatives and that of a given test under shifted alternatives. We also present some simulation results. They attest to consistency of theoretical results with observed empirical powers for quite small sample sizes.