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.     

Smoothing the difference-based estimates of variance using variational mode decomposition

We propose a variational mode decomposition approach to estimate the variance function in a nonparametric heteroscedastic fixed design regression model. A data-driven estimator is constructed by applying variational mode decomposition technique to the difference-based initial estimates. The numerical results show that the proposed estimator performs better than the existing variance estimation procedures in the mean square sense.     

Optimal and lead-in adaptive allocation for binary outcomes: A comparison of Bayesian methods

We compare posterior and predictive estimators and probabilities in response-adaptive randomization designs for two- and three-group clinical trials with binary outcomes. Adaptation based upon posterior estimates are discussed, as are two predictive probability algorithms: one using the traditional definition, the other using a skeptical distribution. Optimal and natural lead-in designs are covered. Simulation studies show that efficacy comparisons lead to more adaptation than center comparisons, though at some power loss, skeptically predictive efficacy comparisons and natural lead-in approaches lead to less adaptation but offer reduced allocation variability. Though nuanced, these results help clarify the power-adaptation trade-off in adaptive randomization.     

Women’s experiences of,and attitudes to,maternity education across the perinatal period in Victoria,Australia: A mixed-methods approach

Background

While the provision of maternity education across the perinatal period can increase the confidence and self-efficacy in childbearing women, there is still thought to be a lack of effective educational resources for parenthood. This study, conducted in Victoria, Australia, investigated women’s experiences of, and attitudes to education communicated in maternity service provision.

Alcohol use and strenuous physical activity in college students: A longitudinal test of 2 explanatory models of health behavior

Objective: To help clarify the effect of gender on the bidirectional relationship between alcohol use and strenuous physical activity in college students. Participants: Five hundred twenty-four (52% female) college students recruited in August 2008 and 2009 and followed up in April 2009 and April 2011, respectively. Methods: Participants reported their alcohol use and strenuous physical activity on 2 occasions (baseline and follow-up) spaced approximately 1 or 2 years apart. Results: For females, alcohol use quantity at baseline was associated with increased strenuous physical activity at 1- and 2-year follow-ups, and alcohol use frequency at baseline was associated with decreased strenuous physical activity at 2-year follow-up. For males, alcohol use frequency at baseline predicted decreased strenuous physical activity at 1-year follow-up. Conclusions: Gender differences may be explained from an eating disorders perspective such that women use physical activity as a compensatory strategy to combat potential weight gain from calories consumed during alcohol use.     

Comparing the Experiences of Highly Skilled Labor Migrants in Sweden and Japan: Barriers and Doors to Long-term Settlement

As labor markets become increasingly global, competition among industrialized nations to attract highly skilled workers from abroad has intensified. Spurred by concerns over future economic needs caused by the demographic challenges of an aging population, both Japan and Sweden have joined this global competition. This article examines Japanese and Swedish immigration policies for highly skilled migrants and compares the highly skilled migrants’ experiences in the two countries through interviews with these migrants. Despite Japan and Sweden's completely different approaches to immigration itself, both countries’ policies, as well as the experiences of the skilled migrants, are strikingly similar. Highly skilled migrants experience language barriers and prejudice in both countries, making it difficult to build social networks with natives. Career development seems to be perceived as a common problem, although less so in Sweden, where labor markets are more flexible. Overall, these issues reduce both Japan's and Sweden's ability to retain skilled migrants. While they share similarities, Sweden's famed work–life balance and gender equality give it an edge in the competition for skilled migrants, which Japan does not share. This comparison identifies which social conditions facilitate or impede skilled migrant settlement.     

A Systems Approach to Social Entrepreneurship

Currently, disabilities organizations are increasingly being challenged by the requirement for individualized service, expectations to show personal outcomes, and the need to base their services on evidence-based practices. Social entrepreneurship (SE) is being put forward as an innovative approach for dealing with these challenges. This article presents a systems approach to SE based on a program logic model. This model identifies the input factors (a strong social vision, exploiting opportunities, maximizing resources), throughput strategies (entrepreneurial orientation, critical thinking skills, networking, capacity building), and outcome components (improving people’s lives, community-building, improving society) of SE at the micro, meso, and macro level. Also, the importance of planning for contextual changes as a social entrepreneur is discussed. The article concludes with presenting three inspiring practices regarding SE in the field of disabilities organizations.     

MANAGING ACADEMIC INTERDISCIPLINARY RESEARCH PROJECTS*

This field study provides variables that can be used by practitioners as action levers and by future researchers as the basis for theoretical development. Conclusions from relevant literature and findings from interviews with interdisciplinary research management identified forty variables that were viewed as important to interdisciplinary research project success. After adjusting the data for reliability attenuation, these variables were further analyzed to identify the best prediction equation. The findings suggested that project age or the longevity of the project and open discussion of disagreements were the best predictors of performance.     

Retrospective information on health status and its application for population health measures

Healthy life expectancies are almost always calculated by using health data from cross-sectional surveys. This type of calculation is done partly because data from longitudinal surveys are not always available, and when they are available, they are collected at intervals that are longer than one year. In such cases, collecting health information retrospectively for the years skipped by the survey is useful. The main purpose of this paper is to show how retrospective health information can be used to estimate life expectancies in different health states. Healthy life expectancies are estimated with and without using data on retrospective health information, and the corresponding estimates are compared. The two sets of estimates are similar. We conclude that retrospectively assessed health information based on a one-year recall period can be used to estimate years of life in various health states and that estimates based on such information will closely approximate estimates based on concurrent health information.     

Collinearity, Bias, and Effect Size: Modeling “the” Effect of Track on Achievement

The estimated effect of any factor can be highly dependent on both the model and the data used for the analyses. This article presents an example of the estimated effect of one factor in two different data sets under three different forms of the standard linear model using the effect of track placement on achievement as an example. Some relative advantages and disadvantages of each model are considered. The analyses demonstrate that, given collinearity among the predictor variables, a model with a poorer statistical fit may be useful for some interpretive purposes.