Another look at Huber's estimator: A new minimax estimator in regression with stochastically bounded noise

Huber's estimator has had a long lasting impact, particularly on robust statistics. It is well known that under certain conditions, Huber's estimator is asymptotically minimax. A moderate generalization in rederiving Huber's estimator shows that Huber's estimator is not the only choice. We develop an alternative asymptotic minimax estimator and name it regression with stochastically bounded noise (RSBN). Simulations demonstrate that RSBN is slightly better in performance, although it is unclear how to justify such an improvement theoretically. We propose two numerical solutions: an iterative numerical solution, which is extremely easy to implement and is based on the proximal point method; and a solution by applying state-of-the-art nonlinear optimization software packages, e.g., SNOPT. Contribution: the generalization of the variational approach is interesting and should be useful in deriving other asymptotic minimax estimators in other problems.     

Regularization through variable selection and conditional MLE with application to classification in high dimensions

It is often the case that high-dimensional data consist of only a few informative components. Standard statistical modeling and estimation in such a situation is prone to inaccuracies due to overfitting, unless regularization methods are practiced. In the context of classification, we propose a class of regularization methods through shrinkage estimators. The shrinkage is based on variable selection coupled with conditional maximum likelihood. Using Stein's unbiased estimator of the risk, we derive an estimator for the optimal shrinkage method within a certain class. A comparison of the optimal shrinkage methods in a classification context, with the optimal shrinkage method when estimating a mean vector under a squared loss, is given. The latter problem is extensively studied, but it seems that the results of those studies are not completely relevant for classification. We demonstrate and examine our method on simulated data and compare it to feature annealed independence rule and Fisher's rule.     

Modified inference about the mean of the exponential distribution using moving extreme ranked set sampling

The maximum likelihood estimator (MLE) and the likelihood ratio test (LRT) will be considered for making inference about the scale parameter of the exponential distribution in case of moving extreme ranked set sampling (MERSS). The MLE and LRT can not be written in closed form. Therefore, a modification of the MLE using the technique suggested by Maharota and Nanda (Biometrika 61:601–606, 1974) will be considered and this modified estimator will be used to modify the LRT to get a test in closed form for testing a simple hypothesis against one sided alternatives. The same idea will be used to modify the most powerful test (MPT) for testing a simple hypothesis versus a simple hypothesis to get a test in closed form for testing a simple hypothesis against one sided alternatives. Then it appears that the modified estimator is a good competitor of the MLE and the modified tests are good competitors of the LRT using MERSS and simple random sampling (SRS).     

Emplaced mobilities: Lisbon as a translocality in the migration journeys of Punjabi Sikhs to Europe

The arrival in Portugal of recent migrants from the Indian subcontinent is normally a secondary movement from within Europe tied to the search for a regular pathway into legal integration in the EU. However, as favourable migration policy is not paired with easy economic integration onward migration is common. We argue that such complex migration strategies cannot be amply explored through an origin–destination model; instead we suggest that a translocal perspective provides a framework to examine connections and experiences of emplacement in places of passage/reception like Lisbon. Through a qualitative study of the migration journeys and emplaced practices of Punjabi migrants in Lisbon, our findings highlight relationality between multiple scales, elucidating how agency and structure interact at micro and macro levels in shaping migration experiences and outcomes. We show how the materiality of local community structures ensures the navigation of daily life in the city and provides pathways toward legality contributing to wider mobility regimes. Moreover, we illustrate how onward migration represents an individual strategy to realise different aspects of integration in other EU destinations challenging nation-state-bound understandings of citizenship/settlement and integration.     

对我国2010年人口普查事后调查工作的若干建议

人口普查不可能100％计数每一个人。世界上许多国家都在人口普查后组织事后调查,使用双系统估计量另行求得一个全国人口真实数的估计数,并以此为标准估计人口普查的净遗漏率。我国历次人口普查后都进行了事后调查,其主要缺陷是未对抽取的样本事后分层,未估计“全国真实的人口数”。建议我国2010年事后调查方案在克服这两个缺陷的基础上科学确定全国的样本总量。实行两步抽样等。     

Exploring types of interference between work and non-work: using a diary study approach

Studies of work and family issues have used predominately between-subject cross-sectional designs. While some researchers have called for more longitudinal studies, others have suggested that a more strategic way forward for the field is the use of daily diary studies (Frone, Russell, & Cooper, 1992). This study explores different types of interference between work and non-work domains, using a diary study methodology. This study consisted of a two-week diary study among 12 Irish employees. Analysis involved a two-step procedure involving both content analysis and interpretative phenomenological analysis (IPA). Results indicated that while individuals reported strain-based and time-based interference, evidence was also found of interference concerning persistent and intrusive thoughts. Despite some limitations to the study, this paper demonstrates that diary studies represent an opportunity for researchers to explore work and non-work experiences in a sensitive and ecologically valid way.     

A cross-cultural study on surrogate mother's empathy and maternal–foetal attachment

BackgroundTraditional and gestational surrogate mothers assist infertile couples by carrying their children. In 2005, a meta-analysis on surrogacy was conducted but no study had examined empathy and maternal–foetal attachment of surrogate mothers. Assessments of surrogate mothers show no sign of psychopathology, but one study showed differences on several MMPI-2 scales compared to a normative sample: surrogate mothers identified with stereotypically masculine traits such as assertiveness and competition. They had a higher self-esteem and lower levels of anxiety and depression.Research objectiveTo determine if there is a difference in empathy and maternal–foetal attachment of surrogate mothers compared to a comparison group of mothers.MethodsThree groups of European traditional and gestational surrogate mothers (n = 10), Anglo-Saxon traditional and gestational surrogate mothers (n = 34) and a European normative sample of mothers (n = 32) completed four published psychometric instruments: the Interpersonal Reactivity Index (empathy index), the Hospital Anxiety and Depressions Scale and the MC20, a social desirability scale. Pregnant surrogate mothers filled the Maternal Antenatal Attachment Scale (n = 11). Statistical non-parametric analyses of variance were conducted.FindingsDepending on cultural background, surrogate mothers present differences in terms of empathy, anxiety and depression, social desirability and quality of attachment to the foetus compared to a normative sample.ConclusionsEnvironment plays a role for traditional and gestational surrogacy. Surrogate mothers of both groups are less anxious and depressed than normative samples. Maternal–foetal attachment is strong with a slightly lower quality of attachment. Surrogate mother's empathy indexes are similar to normative samples, sometimes higher.     

In search of family-friendly careers? Professional strategies,work conditions and gender differences in work–family conflict

The aim of this paper is to investigate whether women in a dual-earner context acquire family-friendly jobs as a strategy to keep work–family conflict down. The analysis is based on a survey of newly graduated highly educated men and women in five occupations in Sweden (n?≈?2400). The sample was stratified by occupation and gender to minimize the influence of factors other than gender. The results show that women are more family-oriented, but also more career-oriented than men in their professional strategies. In their jobs, women have less control over work and schedules than men but a similar level of work demands. However, women face lower requirements for employer flexibility (e.g. frequent over time) and this is related to their professional strategies. Finally, women report a higher level of work–family conflict than men in the same occupation, but this gender difference becomes non-significant when accounting for women’s lower level of control. In sum, women in this sample clearly aim for both family and career and do not acquire family-friendly jobs, but aim to avoid ‘family-unfriendly’ requirements for constant availability. To some extent, this enables them to limit their work–family conflict but due to their lower control over work, women still experience more conflict than men in the same occupation.     

Stretching the borders: how international business travel affects the work–family balance

This study examined the consequences of international business travel for the balance between work–family domains by exploring how international business travellers and travellers’ partners manage the boundaries between work and family in order to maintain the balance. Interpretative phenomenological analysis was used in analysing the semi-structured interviews of 10 male travellers and 10 partners. Because of its irregular nature, international business travel affects the personal life and the family of business travellers. Work-related travel also has an impact on how travellers and their partners construct, manage and negotiate borders between work and family in order to avoid an imbalance between these domains. Integration of work and family is usually inevitable in international business traveler families. Integration may lead to role blurring and thus lead to imbalance.     

The significance of meaning. Why IPBES needs the social sciences and humanities

The term “biodiversity” is often used to describe phenomena of nature, which can be studied without a reference to the socially constructed, evaluative, or indeed normative contexts. In our paper, we challenge this conception by focusing particularly on methodological aspects of biodiversity research. We thereby engage with the idea of interdisciplinary biodiversity research as a scientific approach directed at the recognition and management of contemporary society in its ecological embedding. By doing this, we explore how research on and assessments of biodiversity can be enhanced if meaning, aspiration, desires, and related aspects of agency are methodically taken into account. In six sections, we substantiate our claim that the discourse on biodiversity (including the IPBES (Intergovernmental science-policy Platform on Biodiversity and Ecosystem Services) debate) is incomplete without contributions from the social sciences and humanities. In the introduction, a brief overview of biodiversity’s conceptual history is provided showing that “biodiversity” is a lexical invention intended to create a strong political momentum. However, that does not impede its usability as a research concept. Section 2 examines the origins of the Convention on Biological Diversity (CBD) by way of sociological discourse analysis. Subsequently, it proposes a matrix as a means to structure the ambiguities and tensions inherent in the CBD. The matrix reemphasizes our main thesis regarding the need to bring social and ethical expertise to the biodiversity discourse. In Section 3, we offer a brief sketch of the different methods of the natural and social sciences as well as ethics. This lays the groundwork for our Section 4, which explains and illustrates what social sciences and ethics can contribute to biodiversity research. Section 5 turns from research to politics and argues that biodiversity governance necessitates deliberative discourses in which participation of lay people plays an important role. Section 6 provides our conclusions.