Simple Priorities and Core Stability in Hedonic Games

In this paper we study hedonic games where each player views every other player either as a friend or as an enemy. Two simple priority criteria for comparison of coalitions are suggested, and the corresponding preference restrictions based on appreciation of friends and aversion to enemies are considered. We characterize internally stable coalitions on the proposed domains and show how these characterizations can be used for generating a strict core element in the first case and a core element in the second case. Moreover, we prove that an element of the strict core under friends appreciation can be found in polynomial time, while finding an element of the core under enemies aversion is NP-hard.     

Identifying health inequalities between Māori and non‐Māori using mortality tables

Abstract

While there is a need for more detailed information on health inequality to guide public health policy, the most complete and easily available data remain those in mortality tables. We investigate, via a comparative analysis of data from New Zealand on Māori and non‐Māori mortality, whether more detailed information than raw life expectancy may be extracted from the mortality tables. Given a parametric distribution for the mortality capable of fitting irregularities in mortality table data, the curvature of the survival and hazard rates can identify changes in mortality rates, such as infant and late‐life adult mortality, which allows for straightforward comparisons between the two sub‐populations. Our results identify an exogenous effect in earlier mortality among Maori, which correlates well with many published observations of health and health‐care inequalities between Māori and non‐Māori. This “proof of concept” for our method of analysis indicates that examination of bulk data such as those in mortality tables has a potential role in the design of more detailed studies involving causes of mortality.     

Parameter Estimation for Bivariate Shock Models with Singular Distribution for Censored Data with Concomitant Order Statistics

When two‐component parallel systems are tested, the data consist of Type‐II censored data X_(i), i= 1, n, from one component, and their concomitants Y _[i] randomly censored at X_(r), the stopping time of the experiment. Marshall & Olkin's (1967) bivariate exponential distribution is used to illustrate statistical inference procedures developed for this data type. Although this data type is motivated practically, the likelihood is complicated, and maximum likelihood estimation is difficult, especially in the case where the parameter space is a non‐open set. An iterative algorithm is proposed for finding maximum likelihood estimates. This article derives several properties of the maximum likelihood estimator (MLE) including existence, uniqueness, strong consistency and asymptotic distribution. It also develops an alternative estimation method with closed‐form expressions based on marginal distributions, and derives its asymptotic properties. Compared with variances of the MLEs in the finite and large sample situations, the alternative estimator performs very well, especially when the correlation between X and Y is small.     

灰色关联决策分析法在产业投资优势评估中的应用——以近期甘肃省对外招商和经济技术合作为例

本文旨在探讨如何从诸多投资产业中，选择最佳的产业及投资方案。在以往多目标决策法中，当要选择方案时，大都是由主观的判断或是复杂的计算来处理，如此并无法让决策者做整体性之判断。因此，本文使用灰色关联决策分析法，来分析投资方案间之关联度，透过关联度分析结果，除提供投资者做最佳产业及投资方案的选择外，并提供给甘肃省政府拟定政策、投资方案与改善投资环境之参考     

The Women's Movement in South Korea*

Objectives. The objective of the study is to examine the underlying explanations for the relative success of the women's movement in Korea. Building on the resource mobilization model, the present research investigates how women's groups in Korea mobilize resources, increase membership and participation, and pursue alliances and coalitions to achieve their organizational goals. Methods. This research analyzes the data collected via a mail survey of women's groups during November 2000 and May 2001. Results. The study finds that disparate women's organizations (radical vs. reformist) have had distinct resources, strategies, support bases, tactics, and relations to others groups to mobilize more support and effect their goals. Conclusions. From an organizational standpoint, it is clear that democratization brought about an increase in the number of women's organizations that turned women's grievances into a capacity to act collectively.     

Physical capital taxation and labor income taxation in an endogenous growth model with new generations

This paper examines the growth and welfare effects of physical capital taxation and labor income taxation. It is found that the impact of a rise in the physical capital tax rate on the balanced growth rate is crucially related to the birth rate, but a rise in the labor income tax rate definitely reduces the balanced growth rate regardless of the birth rate. It is also found that an increase in the physical capital income tax rate will harm the older but will benefit the younger, while an increase in the labor income tax rate will benefit the older but will harm the younger.

Univariate and Multivariate Value-at-Risk: Application and Implication in Energy Markets

This study investigated the cross-markets price changes, volatility, and shock transmission mechanism among gasoline, crude oil, and diesel spot markets. An asymmetric time-varying volatility model is used to reveal the hidden dynamic shock transmission mechanism among the markets. An iterative optimization Newton–Raphson algorithm is used in the nonlinear estimation procedures by updating the outer product of the gradient vector. The estimated results are used in quantifying the cross-market risk, optimal portfolio holding, and hedging among the energy markets.     

Multivaritate two stage test based on ranks

A distribution free two stage test based on ranks for the multivariate two sample location problem is presented. The asymptotic distribution of the first and second stage test statistics is derived. Results of a Monte Carlo power study are used to compare the two stage test with the usual one stage test. A brief table of critical values is also presented. The test is illustrated by using data from an exercise study conducted by the Multipurpose Arthritis center.