Nonparametric estimation of survival functions for doubly censored observations when the lifetime hazard rate is proportionally related to the censoring hazard rates

Let T, X and Y be non-negative random variables, where T is the time of occurrence of an event of interest, X and Y being the lefl and right censoring variables respectively.

In this paper we propose a nonparametric estimator of the survival function, ST, when T, X and Y are supposed to be independent and their corresponding hazard rates are proportionally related. In this way, our results extend Ebrahimi's work (1985) to the doubly censored data case.     

Socio-material arrangements of impoverished youth in Japan: historical and critical perspectives on neoliberalization

In the past decade, in Japan, a new light has been cast on youth poverty in the context of the middle-class impoverishment caused by the advance of neoliberalization. Thus, the socio-material arrangements, that is, the configuration of people and artifacts pertaining to poor Japanese children, was explored. The authors conducted a field survey in Tokyo’s Adachi Ward, where poverty and the problems it brings have become more serious, and then analyzed that data. In the analysis, we introduced a historical viewpoint to understand the changes in the socio-material arrangements of poor youth that have been brought about by neoliberalization.     

Olson VS. Coase: Coalitional Worth in Conflict

We analyze a model of conflict with endogenous choice of effort, where subsets of the contenders may force the resolution to be sequential: First the alliance fights it out with the rest and – in case they win – later they fight it out among themselves. For three-player games, we find that it will not be in the interest of any two of them to form an alliance. We obtain this result under two different scenarios: equidistant preferences with varying relative strengths, and varying vicinity of preferences with equal distribution of power. We conclude that the commonly made assumption of super-additive coalitional worth is suspect.     

Social welfare and equality

The main purpose of the paper is to provide a unified framework within which normatively significant equality indices can be derived from social welfare orderings. The paper contains a functional representation of the class of social evaluation functions generating relative equality indices.A preliminary version of this paper was written while the second author was visiting the ISI. Financial support from the CAICYT project No. DI-87075, is greatefully acknowledged. We are grateful to W. Bossert and C. Blackorby for comments and useful discussion. The final version of the paper has greatly benefited from the suggestion of an anonymous referee.     

Variance reduction in the study of a test concerning the behrens-fisher problem

A simulation case study illustrating the implementation of a variance reduction technique appropriate for dichotomous response variables is presented. In this simulation study, concerning the power of the Cochran and Cox test for the equality of means under possibly unequal variances, variance reductions of around 80% or more are obtained. More importantly, a known property of the Cochran and Cox, its conservative character, is detected thanks to the use of variance reduction.     

Comparison of web and mail surveys in collecting illicit drug use data: a randomized experiment

This randomized experiment examined survey mode effects for self-reporting illicit drug use by comparing prevalence estimates between a Web-based survey and a mail-based survey. A random sample of 7,000 traditional-aged undergraduate students attending a large public university in the United States was selected to participate in the spring of 2001. Students were randomly assigned to self-administer a survey via the Web or U.S. mail. The Web survey produced a significantly higher response rate than the U.S. mail survey. The prevalence estimates of illicit drug use (lifetime and past year) did not differ significantly between the two survey modes. The findings provide preliminary evidence that Web and U.S. mail surveys produce similar results regarding illicit drug use among undergraduate students. Although additional research is needed involving more diverse samples, these findings bode well for using Web surveys in college-based research.     

Evaluation of the Productivity Decrease Risk Due to a Future Increase in Tropical Cyclone Intensity in Japan

A number of scientists have recently conducted research that shows that tropical cyclone intensity is likely to increase in the future. This would result in an increase in the damage along with a decrease in economic productivity due to precautionary cessation of the economic activity of the affected areas during the passage of the cyclone. The economic effect of this stop in economic activity is a phenomenon that has not received much attention in the past, and the cumulative effect that it can have on the Japanese economy over the next 75 years has never been evaluated. The starting point for the evaluation of the economic risks is the change in the patterns of tropical cyclone intensity suggested by Knutson and Tuleya.⁽ 1 ⁾ The results obtained show how a significant decrease in the overall productivity of the country could be expected, which could lower GDP by between 6% and 13% by 2085.     

Unveiling Research Trends for Organizational Reputation in the Nonprofit Sector

VOLUNTAS: International Journal of Voluntary and Nonprofit Organizations - Public scrutiny and the need for funds in a more competitive environment are pressuring nonprofits to be more consciously...