Unit Root Tests in the Presence of Multi-Variance Break and Level Shifts That Have Power Against the Piecewise Stationary Alternative

Structural breaks in the level as well as in the volatility have often been exhibited in economic time series. In this paper, we propose new unit root tests when a time series has multiple shifts in its level and the corresponding volatility. The proposed tests are Lagrangian multiplier type tests based on the residual's marginal likelihood which is free from the nuisance mean parameters. The limiting null distributions of the proposed tests are the χ²distributions, and are affected not by the size and the location of breaks but only by the number of breaks.

We set the structural breaks under both the null and the alternative hypotheses to relieve a possible vagueness in interpreting test results in empirical work. The null hypothesis implies a unit root process with level shifts and the alternative connotes a stationary process with level shifts. The Monte Carlo simulation shows that our tests are locally more powerful than the OLSE-based tests, and that the powers of our tests, in a fixed time span, remain stable regardless the number of breaks. In our application, we employ the data which are analyzed by Perron (1990), and some results differ from those of Perron's (1990).     

Supplementing a survey with respondent Twitter data to measure e-cigarette information exposure

ABSTRACT

Social media data are increasingly used by researchers to gain insights on individuals’ behaviors and opinions. Platforms like Twitter provide access to individuals’ postings, networks of friends and followers, and the content to which they are exposed. This article presents the methods and results of an exploratory study to supplement survey data with respondents’ Twitter postings, networks of Twitter friends and followers, and information to which they were exposed about e-cigarettes. Twitter use is important to consider in e-cigarette research and other topics influenced by online information sharing and exposure. Further, Twitter metadata provide direct measures of user’s friends and followers as opposed to survey self-reports. We find that Twitter metadata provide similar information to survey questions on Twitter network size without inducing recall error or other measurement issues. Using sentiment coding and machine learning methods, we find Twitter can elucidate on topics difficult to measure via surveys such as online expressed opinions and network composition. We present and discuss models predicting whether respondents’ tweet positively about e-cigarettes using survey and Twitter data, finding the combined data to provide broader measures than either source alone.     

Investigating Differences in How the News Media Views Homosexuality Across Nations: An Analysis of the United States,South Africa,and Uganda

While there is a wealth of information about the extent to which people across the world disapprove of homosexuality, we know a lot less about the lenses through which they view same‐sex relations. The aim of this study is to understand better how homosexuality is framed in the public press, and how religion and economic development may combine to shape this discourse. Through an analysis of almost 400 newspaper articles, this study compares how homosexuality is framed in Uganda, South Africa, and the United States. Because these nations have high levels of religious belief, but differ in their level of economic development and democracy, we can assess how these factors interact to shape portrayals. Drawing on work from cultural sociology and the sociology of religion, this study shows that the United States is much more likely than Uganda to frame homosexuality as a civil rights issue and use entertainers as claimsmakers. Conversely, articles from Uganda are more likely than those from the United States or South Africa to frame homosexuality as a religious issue and draw on religious claimsmakers. Likewise, Uganda is much more likely than South Africa to discuss homosexuality in the context of Western influences.     

Children and marital dissolution in China

Journal of Population Research - Using data for women from the 2010, 2012 and 2014 Chinese Family Panel Studies, this study investigated several aspects of children’s effects on the risk of...     

A qualitative study of innovations implemented to improve transition of care from maternity to child and family health (CFH) services in Australia

BackgroundThe transition of care (ToC) from maternity services, particularly from midwifery care to child and family health (CFH) nursing services, is a critical time in the support of women as they transition into early parenting. However significant issues in service provision exist, particularly meeting the needs of women with social and emotional health risk factors. These include insufficient resources, poor communication and information transfer, limited interface between private and public health systems and tension around role boundaries. In response some services are implementing strategies to improve the transition of care from maternity to CFH services.AimThis paper describes a range of innovations developed to improve transition of care between maternity and child and family health services and identifies the characteristics common to all innovations.MethodsData reported were collected in phase three of a mixed methods study investigating the feasibility of implementing a national approach to child and family health services in Australia (CHoRUS study). Data were collected from 33 professionals including midwives, child and family health nurses, allied health staff and managers, at seven sites across four Australian states. Data were analysed thematically, guided by Braun and Clarke's six-step process of thematic analysis.FindingsThe range of innovations implemented included those which addressed; information sharing, the efficient use of funding and resources, development of new roles to improve co-ordination of care, the co-location of services and working together. Four of the seven sites implemented innovations that specifically targeted families with additional needs. Successful implementation was dependent on the preliminary work undertaken which required professionals and/or organisations to work collaboratively.ConclusionImproving the transition of care requires co-ordination and collaboration to ensure families are adequately supported. Collaboration between professionals and services facilitated innovative practice and was core to successful change.     

Learning about Difference, Learning with Others, Learning to Transgress

Emerging work in intergroup contact has vitalized a focus on processes affecting the impact of interventions on outcomes. We theorized that intergroup learning—learning about other groups, educating others about one's own groups, intention to bridge intergroup differences, and reflecting on one's own group—mediates the effect of a combined enlightenment-encounter curricular intervention on assessments of importance and confidence in taking action to reduce prejudice and promote diversity. Results from a pretest/posttest design with a diverse group of undergraduate social welfare majors (n = 175) show (a) increased motivation for intergroup learning, and importance of taking action, and confidence in doing so, and (b) intergroup learning partially or fully mediates the impact of enlightenment and/or encounter on taking action .     

Left-Side strong increases in risk and their comparative statics

This paper introduces a new concept of left-side strong increases in risk (L-SIR) that extends the definition of strong increases in risk (SIR). We also provide somewhat stronger restrictive set of risk-averse decision-makers with a non-negative third derivative utility (prudence) to obtain an appealing comparative statics result for L-SIR.The authors gratefully acknowledge the helpful comments and suggestions of an anonymous referee     

Outcomes assessment of role-play scenarios for teaching responsible conduct of research

We describe the summative assessment of role-play scenarios that we previously developed to teach central topics in the responsible conduct of research (RCR) to graduate students in science and engineering. Interviews with role-play participants, with participants in a case discussion training session, and with untrained students suggested that role-playing might promote a deeper appreciation of RCR by shifting the focus away from wanting to simply "know the rules." We also present the results of a think-aloud case analysis study and describe the development of a behaviorally-anchored rating scale (BARS) to assess participants' case analysis performance.     

Fire scheduling for planned artillery attack operations under time-dependent destruction probabilities

In this paper, we consider the fire scheduling problem (FSP) for field artillery, which is the problem of scheduling operations of firing at given targets with a given set of weapons. We consider a situation in which the number of available weapons is smaller than the number of targets, the targets are assigned to the weapons already, and targets may move and hence the probability that a target is destroyed by a firing attack decreases as time passes. We present a branch and bound algorithm for the FSP with the objective of minimizing total threat of the targets, which is expressed as a function of the destruction probabilities of the targets. Results of computational tests show that the suggested algorithm solves problems of a medium size in a reasonable amount of computation time.