Motivated by a breast cancer research program, this paper is concerned with the joint survivor function of multiple event times when their observations are subject to informative censoring caused by a terminating event. We formulate the correlation of the multiple event times together with the time to the terminating event by an Archimedean copula to account for the informative censoring. Adapting the widely used two-stage procedure under a copula model, we propose an easy-to-implement pseudo-likelihood based procedure for estimating the model parameters. The approach yields a new estimator for the marginal distribution of a single event time with semicompeting-risks data. We conduct both asymptotics and simulation studies to examine the proposed approach in consistency, efficiency, and robustness. Data from the breast cancer program are employed to illustrate this research.
In the current investigation, idiosyncratic deals (i-deals; individualized work arrangements) are modeled as differentiated resources that shape leader-member exchange (LMX) relationships in workgroups. We integrate literature on leader-member exchange (LMX) with research on i-deals to argue that employee evaluations of i-deals received from the grantor –typically the leader- enhance employee perceptions of LMX, which in turn become instrumental in generating positive performance outcomes. Furthermore, because workgroup characteristics have potential implications on the relationship between a deal grantor and the deal recipient, drawing upon social identity theory of leadership, we reason that the i-deals-LMX relationship is affected by the overall value congruence among the group members. Cross-level moderated mediation analyses on multi source data obtained from 289 employees nested in 60 workgroups showed that the mediational role of LMX in the i-deals to performance outcomes relationship was weaker in high value congruence groups. 相似文献
We propose testing procedures for the hypothesis that a given set of discrete observations may be formulated as a particular time series of counts with a specific conditional law. The new test statistics incorporate the empirical probability-generating function computed from the observations. Special emphasis is given to the popular models of integer autoregression and Poisson autoregression. The asymptotic properties of the proposed test statistics are studied under the null hypothesis as well as under alternatives. A Monte Carlo power study on bootstrap versions of the new methods is included as well as real-data examples. 相似文献
