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 this paper we introduce a new definition of strategy-proofness for multi-valued social choice correspondences. We prove
two Gibbard-Satterthwaite type results for strategy-proof social choice correspondences. These results show that allowing
multiple outcomes as social choices will not necessarily lead to an escape from the Gibbard-Satterthwaite impossibility theorem.
Received: 24 January 2001/Accepted: 19 March 2001 相似文献
Qualitative Sociology - The upsurge of Chinese language media—publications, radio, television, and the Internet—mirrors the linguistic, cultural, and socioeconomic diversity of the... 相似文献