Educational Homogamy and Gender-Specific Earnings: Sweden, 1990–2009

Several studies have shown strong educational homogamy in most Western societies, although the trends over time differ across countries. In this article, we study the connection between educational assortative mating and gender-specific earnings in a sample containing the entire Swedish population born 1960–1974; we follow this sample from 1990 to 2009. Our empirical strategy exploits a longitudinal design, using distributed fixed-effects models capturing the impact of partner education on postmarital earnings, relating it to the income development before union formation. We find that being partnered with someone with more education (hypergamy) is associated with higher earnings, while partnering someone with less education (hypogamy) is associated with lower earnings. However, most of these differences in earnings emerge prior to the time of marriage, implying that the effect is explained by marital selection processes rather than by partner education affecting earnings. The exception is hypogamy among the highly educated, for which there are strong indications that in comparison with homogamy and hypergamy, earnings grow slower after union formation.     

Factors contributing to the perpetration of workplace incivility: the importance of organizational aspects and experiencing incivility from others

In recent years a growing amount of research has been conducted in the area of workplace incivility. Whereas many studies have focused on the victims and the consequences of incivility, little attention has been paid to the perpetrators and antecedents of workplace incivility. This study aims to identify possible antecedents of workplace incivility, by investigating organizational aspects as well as the possibility that being the target of incivility from co-workers and supervisors could induce incivility. A total of 512 employees (378 women and 133 men) in the school sector in a Swedish municipality completed an online questionnaire. Overall, the results of structural equation modelling analyses showed that organizational variables were related to the perpetration of incivility. A direct relationship was found between being uncivil and organizational change, job insecurity, low social support from co-workers and high job demands. However, the strongest relationship was found between experienced incivility from co-workers and instigated incivility. This could be reflecting a climate or culture of incivility in the organization, and carry implications for future practice in interventions against workplace incivility. The results indicate the importance of focusing on the perspective of the instigator to gain knowledge about the process of workplace incivility.     

A Likelihood Ratio Test for Idiosyncratic Unit Roots in the Exact Factor Model with Integrated Factors

We consider an exact factor model with unobservable common stochastic trends imposed by non-stationary factors, and study, by simulation, the power of the likelihood ratio test for unit roots in the idiosyncratic components. The power of the test is compared with the analogous Lagrange multiplier test and the Fisher-type test proposed by Bai and Ng. The results suggest that the benefit of the likelihood ratio test is in panels with a small cross-section.     

The Use of Investigations in the Introductory Statistics Course

Reasons for including investigations in a first course in statistics are presented. Investigations create an environment of participation and give the student the opportunity to experience statistics in action. This participation highlights the interaction between science and statistics. Suggestions are made regarding the integration of investigations into a formal course environment. One investigation is presented in detail. Thirteen other investigations are outlined. Emphasis is placed on experiments that require minimal set-up time yet illustrate important statistical concepts.     

Analogies for Helping Clinicians and Investigators Better Understand the Principles and Practice of Biostatistics

For the interaction between the biostatistician and the clinician or research investigator to be successful, it is important not only for the investigator to be able to explain biological and medical principles in a way that can be understood by the biostatistician, so, too, the biostatistician needs tools to help the investigator understand both the practice of statistics and specific statistical methods. In our practice, we have found it useful to draw analogies between statistical concepts and familiar medical or everyday ideas. These analogies help to stress a point or provide an understanding on the part of the investigator. For example, explaining the reason for using a nonparametric procedure (a general procedure used when the underlying distribution of the data is not known or cannot be assumed) by comparing it to using broad spectrum antibiotics (a general antibiotic used when the specific bacteria causing infection is unknown or cannot be assumed) can be an effective teaching tool. We present a variety of useful (and hopefully amusing) analogies that can be adopted by statisticians to help investigators at all levels of experience better understand principles and practice of statistics.     

Identifying non-competitive bids in construction contract auctions

Construction contract auctions are characterised by (1) anticipated high outliers due to the presence of non-competitive bids, (2) very small samples and (3) uncertainty of the appropriate underlying density function model of the bids. This paper describes the simultaneous identification of high outliers and density function by systematically identifying and removing candidate (high) outliers and examining the composite goodness-of-fit of the resulting reduced samples with the normal and lognormal density functions. Six different identification strategies are tested empirically by application, both independently and in pooled form, to several sets of auction data gathered from around the world. The results indicate the normal density to be the most appropriate model and a multiple of the auction standard deviation to be the best identification strategy.     

Online algorithms for maximizing weighted throughput of unit jobs with temperature constraints

We consider a temperature-aware online deadline scheduling model. The objective is to schedule a number of unit jobs, with release dates, deadlines, weights and heat contributions, to maximize the weighted throughput subject to a temperature threshold. We first give an optimally competitive randomized algorithm. Then we give a constant competitive randomized algorithm that allows a tradeoff between the maximum heat contribution of jobs and the competitiveness. Finally we consider the multiple processor case and give several tight upper and lower bounds.     

Corporate prediction markets: a tool for predicting market shares

Prediction markets have been applied for various forecasting issues, such as political events or sports. The ability of these markets to collect distributed information in a fast and efficient way provides useful support for corporate planning. A crucial criterion for the quality of the information aggregation process is the liquidity of the market, especially in corporate prediction markets, which typically consist of fewer traders than public markets. The use of automated market makers is one option with which to ensure enough liquidity, but it is always related to some drawbacks. This paper investigates a field study of a corporate prediction market that replaces the automated market maker with human traders. We analyze the efficiency of such markets, the impact of the applied incentive system and the effects of human market makers.     

The benefits of a nap during prolonged work and wakefulness

Abstract

Prolonged work scenarios with demands for sustained performance are increasingly common. Because sleep loss inevitably compromises functioning in such situations, napping has been proposed as a countermeasure. The optimal timing of the nap relative to its benefits for performance and mood is not known, however. To address this issue, 41 healthy adults were permitted a two-hour nap at one of five times during a 56-hour period of intermittent work, with no other sleep. Naps were placed 12 hours apart, near the circadian peak (P) or trough (T), and were preceded by 6(P), 18(T), 30(P), 42(T), or 54(P) hours of wakefulness. Work test bouts occurred every few hours and consisted of a variety of psychomotor and cognitive tasks as well as mood scales completed at the beginning, middle and end of each bout. A total of eight performance and 24 mood parameters were derived from the bouts and compared between groups at all test points prior to and following the naps. An estimate of the extent to which each nap condition differed from the control (P54) condition was derived by totalling the proportion of test points that yielded statistically significant results relative to the total number of tests conducted both before and after naps.

Although all performance and most mood parameters displayed a circadian-modulated deterioration as the protocol progressed, a nap appeared to attentuate the extent of this change in all performance parameters but not in mood parameters. Overall, the timing of the nap across days and within the circadian cycle was irrelevant to its effect on performance, suggesting that it diminished the intrusion of sleepiness into behavioural functioning, even though subjects were phenomenally unaware of this benefit.     

Developmental stability and leadership effectiveness

Developmental stability is the degree to which we can withstand environmental or genetic stressors during development. Fluctuating asymmetry (FA), concerns the extent to which the right and left side of the body is asymmetrical and is one way to measure developmental stability. Two studies were carried out that examined both the predictive value of leader FA with leadership behaviors and its role in facilitating group performance. The first study examined the hypothesis that a leader's FA is correlated with scores on the Multifactor Leadership Questionnaire (MLQ). The results revealed individuals with a more asymmetrical morphology scored higher on the transformational, but not transactional, dimensions of leadership behavior. A second study examined the hypothesis that asymmetrical morphology and leadership effectiveness would share a positive relationship. In this study participants who led a business game exercise, revealed a positive relationship between FA and self-reported well-being and task satisfaction. Importantly, there was also a positive correlation between the leader's FA score and group performance. The role that developmental stability may play in leadership effectiveness is discussed in the wider context of evolutionary psychology.