A varying coefficient approach to estimating hedonic housing price functions and their quantiles

The varying coefficient (VC) model introduced by Hastie and Tibshirani [26 T. Hastie and R. Tibshirani, Varying-coefficient models, J. R. Statist. Soc. (Ser. B) 55 (1993), pp. 757–796.[Web of Science ®] , [Google Scholar]] is arguably one of the most remarkable recent developments in nonparametric regression theory. The VC model is an extension of the ordinary regression model where the coefficients are allowed to vary as smooth functions of an effect modifier possibly different from the regressors. The VC model reduces the modelling bias with its unique structure while also avoiding the ‘curse of dimensionality’ problem. While the VC model has been applied widely in a variety of disciplines, its application in economics has been minimal. The central goal of this paper is to apply VC modelling to the estimation of a hedonic house price function using data from Hong Kong, one of the world's most buoyant real estate markets. We demonstrate the advantages of the VC approach over traditional parametric and semi-parametric regressions in the face of a large number of regressors. We further combine VC modelling with quantile regression to examine the heterogeneity of the marginal effects of attributes across the distribution of housing prices.     

Computing A-optimal and E-optimal designs for regression models via semidefinite programming

In semidefinite programming (SDP), we minimize a linear objective function subject to a linear matrix being positive semidefinite. A powerful program, SeDuMi, has been developed in MATLAB to solve SDP problems. In this article, we show in detail how to formulate A-optimal and E-optimal design problems as SDP problems and solve them by SeDuMi. This technique can be used to construct approximate A-optimal and E-optimal designs for all linear and nonlinear regression models with discrete design spaces. In addition, the results on discrete design spaces provide useful guidance for finding optimal designs on any continuous design space, and a convergence result is derived. Moreover, restrictions in the designs can be easily incorporated in the SDP problems and solved by SeDuMi. Several representative examples and one MATLAB program are given.     

Vocational Experiences and Quality of Life of Migrants: Overview and Future Research

Quality of life is a complicated concept that has attracted broad attention from multiple disciplines. This article introduces a set of studies that employ diverse approaches to explore how work, vocational, and career experiences shape quality of life among migrants, and proposes a future agenda to extend this stream of research. Specifically, operationalizing quality of life in different ways, research showcased in this special issue has demonstrated how international and intranational migrants achieve, maintain, and enhance their well-being in different life domains. Reflecting on the literature and the showcased studies, this article proposes that future research should advance the current inquiry by better categorizing vocational experiences, uniquely operationalizing of quality of life in migration contexts, taking a more culturally sensitive perspective, and broadening methodological approaches.     

The Life Course,Cohort Dynamics,and International Differences in Aging Trajectories

In recent years, population health research has focused on understanding the determinants of later-life health. Two strands of that work have focused on (1) international comparisons of later-life health and (2) assessing the early-life origins of disease and disability and the importance of life course processes. However, the less frequently examined intersection of these approaches remains an important frontier. The present study contributes to the integration of these approaches. We use the Health and Retirement Study family of data sets and a cohort dynamic approach to compare functional health trajectories across 12 high-income countries and to examine the role of life course processes and cohort dynamics in contributing to variation in those trajectories. We find substantial international variation in functional health trajectories and an important role of cohort dynamics in generating that variation, with younger cohorts often less healthy at comparable ages than the older cohorts they are replacing. We further find evidence of heterogeneous effects of life course processes on health trajectories. The results have important implications for future trends in morbidity and mortality as well as public policy.     

Is Chinese National Health Insurance Effective in the Face of Severe Illness? A Perspective from Health Service Utilization and Economic Burden

Over the past decade, health insurance coverage has expanded dramatically in China. Health insurance benefits, however, remain shallow or ambiguous. This study examines the effect of Chinese national health insurance policy on health service utilization and economic burden in urban settings using the Urban Resident Basic Medical Insurance Household Survey. We employ the Heckman selection model to correct for selection bias among hospital inpatients, and find that compared to individuals without health insurance, those with health insurance are more likely to be admitted to the hospital when their physicians recommended them to enter the hospital as inpatients. Health insurance is also associated with about 45.6 % decrease in out-of-pocket inpatient expenditures. Individuals with urban employee basic medical insurance see the largest decrease in economic burden, followed by individuals with urban resident basic medical Insurance, and those with new rural cooperative medical insurance.     

跨国实践中的社会地位补偿——华南侨乡两个移民群体文化馈赠的比较研究

中国改革开放以来,海外华人移民通过文化馈赠这种跨国实践极大地促进了东南沿海地区的发展。但从我们的观察来看,不同类型的移民群体的跨国实践模式不尽相同。本文借鉴以往国际移民与跨国主义的研究,从社会学的角度提出"社会地位补偿"的范式,对分别来自广东五邑开平与海南文昌下辖两个镇的移民群体进行比较。通过分析,我们发现移民对于侨乡的文化馈赠不仅受到其个人出国前后社会地位变化的制约,而且还受多种客观因素的制约。特定的祖籍国和移居国在世界政治经济地理格局中位置的差异,移民群体在移居地的不同社会境遇以及侨乡的地方政府和地方社会均对文化馈赠产生不同程度的影响。上述这些宏观、中观与微观层面的因素交互作用,形成社会地位补偿的特殊机制,影响移民跨国实践中的文化馈赠。     

残疾儿童社会保障制度的研究

目前,政府通过发展社会保障以增进社会和谐的政策方向基本确立,倡导残疾儿童社会保障制度的适度公正机制是基于经济发展和现代社会平等两者之间的权衡。目的是使社会成员都能够普遍以适度标准不断享受经济社会发展的成果,从而有效地实现社会整合。我国已经初步具备实现残疾儿童社会保障制度的适度公正目标的条件,基于此目标,残疾儿童的社会保障制度仍存在以下制约瓶颈：相关社会保障制度建设法规滞后;政府保障主体地位缺失,财政经费投入不足;残疾儿童参与社会保障层次低、覆盖面窄;保障政策执行部门行政多头管理。因此,残疾儿童社会保障制度的制度设计需要着重于：保持经济发展水平下残疾儿童保障支付享受标准;倡导公正和能动的残疾儿童权利保障价值取向：界定政府责任边界和立法,广泛动员社会力量;整合政府部门残疾儿童社会保障资源。     

Who Is Supporting Homeless Youth? Predictors of Support in Personal Networks

Homeless youth lack the traditional support networks of their housed peers, which increases their risk for poor health outcomes. Using a multilevel dyadic analytic approach, this study identified characteristics of social contacts, relationships, and social networks associated with the provision of tangible and emotional support to homeless youth (N = 419, M age = 20.09, SD = 2.80). Support providers were likely to be family members, sex partners, or non–street‐based contacts. The provision of support was also associated with contacts' employment and homelessness status, frequency of contact, shared risk behaviors, and the number of network members that were homeless and employed. The results provide insights into how homeless youth could be assisted to develop more supportive social networks.