Bayesian Survival Analysis in Proportional Hazard Models with Logistic Relative Risk

Abstract.  The traditional Cox proportional hazards regression model uses an exponential relative risk function. We argue that under various plausible scenarios, the relative risk part of the model should be bounded, suggesting also that the traditional model often might overdramatize the hazard rate assessment for individuals with unusual covariates. This motivates our working with proportional hazards models where the relative risk function takes a logistic form. We provide frequentist methods, based on the partial likelihood, and then go on to semiparametric Bayesian constructions. These involve a Beta process for the cumulative baseline hazard function and any prior with a density, for example that dictated by a Jeffreys-type argument, for the regression coefficients. The posterior is derived using machinery for Lévy processes, and a simulation recipe is devised for sampling from the posterior distribution of any quantity. Our methods are illustrated on real data. A Bernshtĕn–von Mises theorem is reached for our class of semiparametric priors, guaranteeing asymptotic normality of the posterior processes.     

ON GENDER GAPS AND SELF‐FULFILLING EXPECTATIONS: ALTERNATIVE IMPLICATIONS OF PAID‐FOR TRAINING

This paper presents a model of self‐fulfilling expectations by firms and households which generates multiplicity of equilibria in pay and housework time allocation for ex‐ante identical spouses. Multiplicity arises from statistical discrimination exerted by firms in the provision of paid‐for training to workers, rather than from incentive problems in the labor market. Employers' beliefs about differences in spouses' reactions to housework shocks lead to symmetric (ungendered) and asymmetric (gendered) equilibria. We find that: (1) the ungendered equilibrium tends to prevail as aggregate productivity in the economy increases (regardless of the generosity of family aid policies), (2) the ungendered equilibrium could yield higher welfare under some scenarios, and (3) gender‐neutral job subsidies are more effective that gender‐targeted ones in removing the gendered equilibrium. (JEL J16, J70, J71)     

CRITIQUE DE LA THEORIE LIBERALE DU DEVELOPPEMENT

To this day, the development programs proposed for underdeveloped countries have met with little success because the economic analysis which encompasses them takes into account only the technique and data of macro-economics and ignores social relations. It is this weakness of the analysis that caused Western experts to be unaware of the effects of imperialism on the Third World, the evolution particular to underdeveloped countries that A.G. Frank called "development of underdevelopment." This evolution, characterized by the exploitation of Third World resources in the interests of the West, must be thwarted by a firmer, more independent stand on the part of the underdeveloped countries.
Les programmes de développement proposés aux pays sous-développés ont connu peu de succès jusqu'à ce jour. C'est que l'analyse économiste qui les sous-tend ne tient compte que de la technique et des données macro-économiques, ignorant ainsi les rapports sociaux. C'est la faiblesse de l'analyse qui a mené les experts occidentaux à ignorer les effets de l'impérialisme sur le Tiers-Monde, cette évolution spécifique des pays sous-développés que A.G. Frank a appelée « développement du sous-développement >>. Cette évolution, caractérisée par l'exploitation des ressources du Tiers-Monde selon les intérêts de l'Occident, doit être contrecarrée par une prise de position plus ferme et plus indépendante de la part des pays sous-développés.     

WHY CORPORATIONS INSURE

Corporations insure to reduce the shirking-information problem of joint production. Insurance encourages specialization in ownership, increasing the returns to monitoring and lowering shareholders' demand for a more diversified portfolio; it enhances the credibility of specific capital as a performance bond; and it lowers the cost to shareholders of compensating other members of the team for investing in firm-specific assets. Tax and other factors may further encourage individual corporations to insure.     

PEER EFFECTS IN HIGHER EDUCATION: DOES THE FIELD OF STUDY MATTER?

Does the peer effect vary with the field of study? Using data from a middle‐sized public university located in southern Italy and exploiting the random assignment of first‐year students to college accommodation, we find that roommate peer effects for freshmen enrolled in the hard sciences are positive and significantly larger than for freshmen enrolled in the humanities and social sciences. We present a simple theoretical model which suggests that the uncovered differences between fields in the size of the peer effect could plausibly be generated by between‐field variation in labor market returns, which affect optimal student effort. (JEL I21, Z13, J24)     

关于少数民族概念的几个问题－－少数民族权利理论问题研究

“少数民族”一词是一个被广泛使用的概念。“少数民族”概念在各个国家和地区各有不同的界定,每一个国家根据其自身所要调整的民族关系,来定义其特定的少数民族概念,并进而保障少数民族权利。在中国,少数民族概念已经深入人心,这是民族概念在当代中国社会和中国宪法体系中所具有的独特意义和价值。     

Application of TOC/OPT rules in a medium sized shop

Abstract

Abstract. Theory of constraints (TOC) and optimized production technology (OPT) are frequently presented as the better options for production control systems. Despite this enthusiasm, there is very little literature on how these principles can be implemented in practice without having to resort to the expensive proprietary software. In this paper we present a case study in which the OPT/TOC ideas were implemented without using the software. Management's major concern was reduction of work in process and increased delivery performance. It was decided to test whether the ideas of OPT/TOC were applicable in this environment and more importantly to which extent these two performance measures could be improved. The paper reports on the methodology used to test the OPT/TOC ideas in this shop and presents some early results of improvement, as well as some new problems which arose due to the new approach.