A comparison between the two-sample t test and Satterthwaite's approximate F test is made, assuming the choice between these two tests is based on a preliminary test on the variances. Exact formulas for the sizes and powers of the tests are derived. Sizes and powers are then calculated and compared for several situations. 相似文献
This article introduces a new model of trend inflation. In contrast to many earlier approaches, which allow for trend inflation to evolve according to a random walk, ours is a bounded model which ensures that trend inflation is constrained to lie in an interval. The bounds of this interval can either be fixed or estimated from the data. Our model also allows for a time-varying degree of persistence in the transitory component of inflation. In an empirical exercise with CPI inflation, we find the model to work well, yielding more sensible measures of trend inflation and forecasting better than popular alternatives such as the unobserved components stochastic volatility model. This article has supplementary materials online. 相似文献
Effective production scheduling requires consideration of the dynamics and unpredictability of the manufacturing environment. An automated learning scheme, utilizing genetic search, is proposed for adaptive control in typical decentralized factory-floor decision making. A high-level knowledge representation for modeling production environments is developed, with facilities for genetic learning within this scheme. A multiagent framework is used, with individual agents being responsible for the dispatch decision making at different workstations. Learning is with respect to stated objectives, and given the diversity of scheduling goals, the efficacy of the designed learning scheme is judged through its response under different objectives. The behavior of the genetic learning scheme is analyzed and simulation studies help compare how learning under different objectives impacts certain aggregate measures of system performance. 相似文献
Affective reactions to the departure of work group leaders are proposed as an important determinant of members' trust-related judgments regarding new leaders. A field test of veterinary hospital employees evaluating new leaders revealed that the affective reaction to the departure of the prior group leader predicted trust when there was no history between the individuals. When there was history between the two individuals, the group member's evaluation of the new leader's ability on their prior job was a significant predictor of trust over and above their affective reaction to the succession. The relationships between affective reactions to succession and trust formation were replicated in a longitudinal simulation of trust formation in student groups. The implications of these findings for the study of trust in organizations and leadership succession processes in work groups are discussed. 相似文献
I ask whether the highly confrontational collective bargaining in the airlines is unique to that industry or a sign of a deepening
crisis in union–management relations nationally. First, airline labor relations are reviewed in the context of extremely contentious
negotiations, intense industry competition, complex and fragmented bargaining structures, frequent bankruptcies, and unpredictable
external shocks. Next, concessionary bargaining in the airlines is discussed, and a new and extreme form of concessionary
bargaining is identified. The emergence of the new concessionary bargaining in the airlines and its spread to the automobile
sector is then interpreted as the early signs of a fundamental transformation of collective bargaining. The implications of
the new concessionary bargaining are then described at the workplace, company, union, and societal levels.
The widely used methods for estimating adult mortality rates from sample survey responses about the survival of siblings, parents, spouses, and others depend crucially on an assumption that, as we demonstrate, does not hold in real data. We show that when this assumption is violated so that the mortality rate varies with sibship size, mortality estimates can be massively biased. By using insights from work on the statistical analysis of selection bias, survey weighting, and extrapolation problems, we propose a new and relatively simple method of recovering the mortality rate with both greatly reduced potential for bias and increased clarity about the source of necessary assumptions. 相似文献
Micro-sociological theory has traditionally stressed interactional pressures towards alignment: actors’ attempts to co-construct a shared definition of the situation. We argue that this model provides an insufficient account of the coordination of action and of the emergence of intersubjectivity among actors. To complement the focus on alignment, we develop a theory of disruption—a perceived misalignment of the dramaturgical structure of interaction in coordinating expected lines of action. We develop a theory of the interaction order that takes the interplay between interactional alignment and disruption as a foundational challenge both for sociology and for actors in their everyday lives. We focus on the practical ways in which actors negotiate both interactional breaches and wider relational ruptures, and how they differentiate between disruptions-of relations and disruptions-for them. By doing so, we connect the interaction order to a wider relational order, providing a bridge between micro-level interactionism and the sociology of culture.
This commentary critiques Betthäuser, Bourne and Bukodi's (2020) paper which finds that cognitive ability does not substantially mediate class of origin effects on educational and occupational outcomes. From these results, they conclude that cognitive ability is only of minor importance for social stratification, reasserting their view of the primacy of class origins for social stratification. The central issue surrounding cognitive ability in social stratification is its effects on socioeconomic attainments vis-à-vis socioeconomic origins, not the extent that cognitive ability mediates classorigin effects. Their analytical strategy of estimating the extent that cognitive ability mediates class origineffects is misleading because: it ignores the only moderate associations of socioeconomic origins with educational and occupational outcomes; the stronger direct effects of cognitive ability; the associations of parents’ ability with their own socioeconomic attainments; and the genetic transmission of cognitive ability and other traits relevant to social stratification from parents to their children. 相似文献