Promotion Time Cure Rate Model with Bivariate Random Effects

In this article, we consider the inclusion of random effects in both the survival function for at-risk subjects and the cure probability assuming a bivariate normal distribution for those effects in each cluster. For parameter estimation, we implemented the restricted maximum likelihood (REML) approach. We consider Weibull and Piecewise Exponential distributions to model the survival function for non-cured individuals. Simulation studies are performed, and based on a real database we evaluate the performance of our proposed model. Effect of different follow-up times and the effect of considering independent random effects instead of bivariate random effects are also studied.     

From Entrepreneurial Orientation and Learning Orientation to Business Performance: Analysing the Mediating Role of Organizational Learning and the Moderating Effects of Organizational Size

Following the organizational learning theory and the knowledge‐based view approach, this contribution aims to study the influence of entrepreneurial orientation and learning orientation on organizational learning, considering the latter as a mediating variable in the relationships between both antecedent cultural values and business performance. We also analyse the moderating role of organizational size on these previous relationships. The hypotheses proposed in our research model are tested on a sample of 140 Spanish industrial companies, applying variance‐based structural equation modelling: partial least squares. In order to assess the moderating effects of organizational size, we adopt a multi‐group approach using two subsamples with large firms and small and medium‐sized enterprises (SMEs). Our findings indicate that organizational learning partially mediates the relationship between entrepreneurial orientation and performance and fully mediates the link between learning orientation and performance. Likewise, the results reveal that the relationship established between entrepreneurial orientation and organizational learning is more intense for the group of large firms than for the group of SMEs. Moreover, the influence of learning orientation on organizational learning is greater in SMEs than in large firms.     

Socio-economic determinants of suicide in Japan

Japan has the highest suicide rates among the OECD countries and this public health problem seems to be accelerating in over the recent decades. Investigating and understanding the suicidal behaviour is of crucial importance to society and health policy makers. Such an investigation could provide with useful information for those responsible in formulating the national policies on suicide prevention. This study estimates dynamic econometric models for total, male and female suicides in Japan for the period of 1957–2009. Using the ARDL approach to cointegration, we find that the associations of suicide with sociological factors (divorce and fertility rates) were stronger than those with economic factors (per capita GDP and unemployment) for females.     

Power of Enforcement and Dictatorship

A new Arrovian impossibility is obtained without invoking independence of irrelevant alternatives type assumptions. The new conditions leading to the impossibility are based on the concept of power of enforcement, and specify how this power can (see A3) or cannot be expanded (see A1, A2 and A4).     

Weight matrices for social influence analysis: An investigation of measurement errors and their effect on model identification and estimation quality

Weight matrices, such as used in network autocorrelation models, are useful to investigate social influence processes. The objective of this paper is to investigate a key topic that has received relatively little attention in previous research, namely the issues that arise when observational limitations lead to measurement errors in these weight matrices. Measurement errors are investigated from two perspectives: when relevant ties are omitted, and when irrelevant ties are erroneously included as part of the matrix. The paper first shows analytically that these two situations result in biased estimates. Next, a simulation experiment provides evidence of the effect of erroneously coding the weight matrix on model performance and the ability of a network autocorrelation test to identify social influence effects. The results suggest that depending on the level of autocorrelation and the topology attributes of the underlying matrix, there is a window of opportunity to identify and model social influence processes even in situations where the ties in a matrix cannot be accurately observed.     

Some advances in the study of the compatibility of three bivariate copulas

Summary In this paper we study the problem of the compatibility of three bivariate copulas, i.e., we look for conditions which allow us to assure the existence of a three-copula whose two-dimensional margins are given. As a particular case, we seek conditions for two bivariate copulasC ₁ andC ₂ under whichC ₂[C₁ (x, y), z] is a three-copula. We specifically study the compatibility of the copulasM, W andII with other copulas both in general and in the particular case. We also study the compatibility of a two-copula with convex linear combinations of other two-copulas. Several examples illustrate the results obtained in each case, and some applications are given.     

Initial Career and Work Meanings in Seven European Countries

This study explores the initial careers of two target groups of young adults in seven European countries. Career patterns have been constructed through cluster analysis on data gathered from the young adults through a retrospective self-report procedure covering a period of 2.5 years. Six career patterns have been identified across countries by the activities taking place (employment, various educational preparations, unemployment, military or civil service) and have been further described by personal and work-related variables as well as by meaning of work indices (work centrality, intrinsic versus extrinsic work orientations, and societal norms about working) and psychological well-being in the second year on the labor market. Suggestions for further research as well as the implications for career counseling, career education, organizational career guidance and development have been given.     

Positional independence in preference aggregation

If, for strict preferences, a unique choice function (CF) is used to aggregate preferences position-wise then the resulting social welfare function (SWF) is dictatorial. This suggests that the task performed by non-dictatorial SWFs must be “more complex” than just selecting an alternative from a list using a single criterion. This is because the information required by non-dictatorial SWFs to aggregate preferences cannot be compressed into a CF. It is also shown that the attempt to reduce the working of a SWF to the working of a CF involves the adoption of certain positional requirements, whose relationship with the conditions in Arrow's theorem is established. Received: 28 May 2001/Accepted: 25 March 2002 My deepest gratitude to Donald G. Saari, who rescued this paper from the worst fate, and to the referee, who showed the escape route.