Dynamic Identification of Dynamic Stochastic General Equilibrium Models

This paper studies dynamic identification of parameters of a dynamic stochastic general equilibrium model from the first and second moments of the data. Classical results for dynamic simultaneous equations do not apply because the state space solution of the model does not constitute a standard reduced form. Full rank of the Jacobian matrix of derivatives of the solution parameters with respect to the parameters of interest is necessary but not sufficient for identification. We use restrictions implied by observational equivalence to obtain two sets of rank and order conditions: one for stochastically singular models and another for nonsingular models. Measurement errors, mean, long‐run, and a priori restrictions can be accommodated. An example is considered to illustrate the results.     

爱和艺术的可见性与不可见性——论歌德的《亲和力》和本雅明对“无性美学”的批判

在<亲和力>这部歌德的晚期作品中,诗人探求的是"情爱美学",重在"无性美学"的理念.他试图从性的欲望中逃脱出来,寻求一种"无性的圣洁".情爱和性欲作为决定婚姻选择的亲和力,成为引导命运的一种力量.在现实世界中,歌德的"情爱"无法逃脱"爱欲"的支配,注定是失败者.在虚构的世界中, 歌德试图与这一"命运"进行抗争.本文尝试从歌德<亲和力>的创作以及本雅明对歇德的文学批评入手,通过对作品"实在内涵"的分析,探求其"真实内涵",即作品中"不可见"的一面.     

Test for the existence of finite moments via bootstrap

This paper develops a bootstrap hypothesis test for the existence of finite moments of a random variable, which is nonparametric and applicable to both independent and dependent data. The test is based on a property in bootstrap asymptotic theory, in which the m out of n bootstrap sample mean is asymptotically normal when the variance of the observations is finite. Consistency of the test is established. Monte Carlo simulations are conducted to illustrate the finite sample performance and compare it with alternative methods available in the literature. Applications to financial data are performed for illustration.     

Some nonparametric precedence-type tests based on progressively censored samples and evaluation of power

In this paper, we consider the problem of testing the equality of two distributions when both samples are progressively Type-II censored. We discuss the following two statistics: one based on the Wilcoxon-type rank-sum precedence test, and the second based on the Kaplan–Meier estimator of the cumulative distribution function. The exact null distributions of these test statistics are derived and are then used to generate critical values and the corresponding exact levels of significance for different combinations of sample sizes and progressive censoring schemes. We also discuss their non-null distributions under Lehmann alternatives. A power study of the proposed tests is carried out under Lehmann alternatives as well as under location-shift alternatives through Monte Carlo simulations. Through this power study, it is shown that the Wilcoxon-type rank-sum precedence test performs the best.     

Welfare Attitudes of Singaporeans – Ambiguity in Shifting Socio‐political Dynamics

This article presents findings from a survey of 440 Singaporeans on their attitudes towards welfare and welfare recipients. Attitudes were generally favourable, but sentiments towards higher taxes to help the poor were ambivalent. Controlled for demographic characteristics, ‘poverty sympathizers’ and affiliates of opposition political parties held the most liberal views, but were not more willing to pay higher taxes. Instead, poor respondents on the one hand and highly educated respondents on the other hand were more willing to pay higher taxes. Knowledge accumulation and beliefs about causes of poverty were strong predictors of attitudes. Effects of personal values and self‐interest were less evident. Couched against the backdrop of an economy that has experienced rapid transformation and one of the widest income inequality in the developed world, the article discusses the critical juncture of social response and policy choices that Singapore finds itself.     

Robust inference for bivariate point processes

In the analysis of recurrent events where the primary interest lies in studying covariate effects on the expected number of events occurring over a period of time, it is appealing to base models on the cumulative mean function (CMF) of the processes (Lawless & Nadeau 1995). In many chronic diseases, however, more than one type of event is manifested. Here we develop a robust inference procedure for joint regression models for the CMFs arising from a bivariate point process. Consistent parameter estimates with robust variance estimates are obtained via unbiased estimating functions for the CMFs. In most situations, the covariance structure of the bivariate point processes is difficult to specify correctly, but when it is known, an optimal estimating function for the CMFs can be obtained. As a convenient model for more general settings, we suggest the use of the estimating functions arising from bivariate mixed Poisson processes. Simulation studies demonstrate that the estimators based on this working model are practically unbiased with robust variance estimates. Furthermore, hypothesis tests may be based on the generalized Wald or generalized score tests. Data from a trial of patients with bronchial asthma are analyzed to illustrate the estimation and inference procedures.     

A Bayesian-loss function-based method in assessing loss caused by ship-source oil spills in the arctic area

It is difficult to assess the risk of ship-source oil spills in Arctic waters for insurance purposes due to many unknowns and the lack of reliable data. However, maritime activities in the Arctic area continue to grow, indicating the urgent needs for the development of innovative methods to estimate loss from potential ship-source oil spills in the Arctic area. To fill this gap, we develop a hybrid Bayesian-loss function-based method to assess ship-source oil spill-related loss and implement an illustrative test on Baffin Island, Nunavut in Canada. The results confirm that our method can accurately assess loss and, subsequently, develop reliable insurance premiums for shipping activities in the Arctic area. This enables governmental and nongovernmental organizations alike to use the method as a reliable loss estimation mechanism for ship-source oil spills. Also, it is a valuable tool in designing measures for safer and more resilient Arctic shipping.     

Depression Amongst Chinese Adolescents in Hong Kong: An Evaluation of a Stress Moderation Model

Stress has an established association with depression. However, not all adolescents experiencing stressors become depressed and it is helpful to identify potential resilience factors. The current study tests a theoretical extension of a stress-diathesis model of depression in a Chinese context, with stress, coping, family relationships, and alexithymia as risk factors for depression. This community study involves 1,199 secondary school students (567 males and 632 females) aged between 14 and 20 from six high schools with different bandings in Hong Kong. The models tested confirm the relationship between stress and depression. Ability to identify of one’s feelings (alexithymia subscale), the adoption of problem solving coping and the rejection of non-productive coping all acted as protective factors (moderators) against depression in the presence of stress. Coping also partially mediated the relationship between alexithymia and depression. A stress-diathesis model received some support, however, a complex set of inter-relationship between all the explanatory variables was revealed. Problem solving coping and non-productive coping emerged as key factors in understanding adolescent depression.     

Unpacking Self-Rated Health and Quality of Life in Older Adults and Elderly in India: A Structural Equation Modelling Approach

The Study on global AGEing and adult health (SAGE) aims at improving empirical understanding of the health and well-being of older adults in low- and middle-income countries. A total of 321 adults aged 50 years and older were interviewed in rural Pune district, India, in 2007. We used Structural Equation Modelling (SEM) to examine the pathways through which social factors, functional disability, risk behaviours, and chronic disease experience influence self-rated health (SRH) and quality of life (QOL) amongst older adults in India. Both SRH and QOL worsened with increased age (indirect effect) and limitations in functional ability (direct effect). QOL, socio-economic status (SES), and social networking had no significant effect on SRH. Smoking was associated with the presence of at least one chronic illness, but this did not have a statistically significant effect on SRH. Higher social networking was seen amongst the better educated and those with regular income, which in turn positively affected the QOL rating. QOL had a direct, but statistically not significant, effect on SRH. In conclusion, the indirect effects of age on SRH mediated through functional ability, and the effects of SES on QOL mediated through social networking, provide new understanding of how age and socio-economic status affect SRH and QOL. By allowing for measurement errors, solving for collinearity in predictor variables by integrating them into measurement models, and specifying causal dependencies between the underlying latent constructs, SEM provides a strong link between theory and empirics.     

WILCOXON-TYPE RANK-SUM PRECEDENCE TESTS

This paper introduces Wilcoxon‐type rank‐sum precedence tests for testing the hypothesis that two life‐time distribution functions are equal. They extend the precedence life‐test first proposed by Nelson in 1963. The paper proposes three Wilcoxon‐type rank‐sum precedence test statistics—the minimal, maximal and expected rank‐sum statistics—and derives their null distributions. Critical values are presented for some combinations of sample sizes, and the exact power function is derived under the Lehmann alternative. The paper examines the power properties of the Wilcoxon‐type rank‐sum precedence tests under a location‐shift alternative through Monte Carlo simulations, and it compares the power of the precedence test, the maximal precedence test and Wilcoxon rank‐sum test (based on complete samples). Two examples are presented for illustration.