Multiple event times in the presence of informative censoring: modeling and analysis by copulas

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.

     

Doing Good and Selling Goods

VOLUNTAS: International Journal of Voluntary and Nonprofit Organizations - This paper explores a network of organizations and their perspectives on the social enterprise commodity. Based on...     

Tests for time series of counts based on the probability-generating function

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.     

Media Disaster Reporting Effects on Public Risk Perception and Response to Escalating Tornado Warnings: A Natural Experiment

Previous research has evaluated public risk perception and response to a natural hazards in various settings; however, most of these studies were conducted either with a single scenario or after a natural disaster struck. To better understand the dynamic relationships among affect, risk perception, and behavioral intentions related to natural disasters, the current study implements a simulation scenario with escalating weather intensity, and includes a natural experiment allowing comparison of public response before and after a severe tornado event with extensive coverage by the national media. The current study also manipulated the display of warning information, and investigated whether the warning system display format influences public response. Results indicate that (1) affect, risk perception, and behavioral intention escalated as weather conditions deteriorated, (2) responses at previous stages predicted responses at subsequent stages of storm progression, and (3) negative affect predicted risk perception. Moreover, risk perception and behavioral intention were heightened after exposure to the media coverage of an actual tornado disaster. However, the display format manipulation did not influence behavioral responses. The current study provides insight regarding public perception of predisaster warnings and the influence of exposure to media coverage of an actual disaster event.     

The minimum wage and poverty among full-time workers

V. Conclusions The empirical evidence is strong that minimum wages have had little or no effect on poverty in the U.S. Indeed, the evidence is stronger that minimum wages occasionally increase poverty. It also suggests that the minimum wage does not even lower poverty for the one group that, almost by definition, one would expect to be helped: full-time, year-round workers. While the empirical results suggest minimum wages do not achieve what is ostensibly their primary goal — relieving poverty among the working poor — minimum wages do seem to impose a real cost on society in terms of lost income and output. The empirical evidence on work hours suggests that a $1 increase in the minimum wage, far from being almost costless, could conceivably impose income losses to American workers in the $12-15 billion range per year — an amount equal to the “income deficit” of millions of persons counted as poor by the U.S. Bureau of the Census.     

Politics and Scientific Expertise: Scientists, Risk Perception, and Nuclear Waste Policy

To study the homogeneity and influences on scientists'perspectives of environmental risks, we have examined similarities and differences in risk perceptions, particularly regarding nuclear wastes, and policy preferences among 1011 scientists and engineers. We found significant differences ( p 0.05)in the patterns of beliefs among scientists from different fields of research. In contrast to physicists, chemists, and engineers, life scientists tend to: (a)perceive the greatest risks from nuclear energy and nuclear waste management; (b)perceive higher levels of overall environmental risk; (c)strongly oppose imposing risks on unconsenting individuals; and (d)prefer stronger requirements for environmental management. On some issues related to priorities among public problems and calls for government action, there are significant variations among life scientists or physical scientists. We also found that–independently of field of research–perceptions of risk and its correlates are significantly associated with the type of institution in which the scientist is employed. Scientists in universities or state and local governments tend to see the risks of nuclear energy and wastes as greater than scientists who work as business consultants, for federal organizations, or for private research laboratories. Significant differences also are found in priority given to environmental risks, the perceived proximity of environmental disaster, willingness to impose risks on an unconsenting population, and the necessity of accepting risks and sacrifices.     

Career Self‐Efficacy and Perceptions of Parent Support in Adolescent Career Development

The authors examined the relative contributions of both proximal and distal supports to the career interests and vocational self‐efficacy in a multiethnic sample (N = 139) of middle school adolescents. Consistent with Social Cognitive Career Theory, it was found that (a) vocational self‐efficacy and career planning/exploration efficacy consistently predicted young adolescents' career interests across Holland (J. L. Holland, D. R. Whitney, N. S. Cole, & J. M. Richards, 1969) themes; (b) gender and career gender‐typing predicted interests in Realistic, Investigative, and Social careers; and (c) perceived parent support accounted for 29% to 43% of the total unique variance in vocational self‐efficacy for all Holland theme careers.     

Lives in limbo: Temporary Protected Status and immigrant identities

The United States formulates much of its immigration and refugee policy to match economic and political circumstances. We interpret these policy shifts as a set of graduated positions on immigration and refugee flows that attempts to discipline the lives of newcomers and, in so doing, shapes immigrant identities. In this article, we analyse the interplay between the US government and Salvadoran asylum applicants negotiating procedures that grant only temporary relief from deportation via the policy of Temporary Protected Status (TPS). We find that each policy shift results in the strategic renegotiation of asylum applicants’ identities so as to achieve the best opportunity for a successful outcome. Based on Foucault’s ideas of governmentality and Ong’s concept of flexible citizenship, we argue that what appears more superficially as a patchwork strategy of immigration laws and asylum practices may be theorized more deeply as a set of flexible responses by the state that turn on identity construction at different scales, and that aim to mediate transnational relations.     

腔内电光调制激光系统的混沌模拟

采用数值模拟的方法讨论了带反馈的腔內电光调制激光系统功率输出的分叉和混沌行为,得到了输出功率随控制参数变化的分叉图,和一些定量结果。