Conditional time-dependent nonparametric estimators with an application to healthcare production function

ABSTRACT

By using the probabilistic framework of production efficiency, the paper develops time-dependent conditional efficiency estimators performing a non-parametric frontier analysis. Specifically, by applying both full and quantile (robust) time-dependent conditional estimators, it models the dynamic effect of health expenditure on countries’ technological change and technological catch-up levels. The results from the application reveal that the effect of per capita health expenditure on countries’ technological change and technological catch-up is nonlinear and is subject to countries’ specific income levels.     

Reasons That Could Lead People to Divorce in an Evolutionary Perspective: Evidence from Cyprus

In the current research, we aimed to identify the reasons that could drive people to get a divorce. In Study 1, we employed qualitative research methods, and we identified 62 reasons that could potentially drive people to get a divorce. Using quantitative research methods, in Study 2 we classified these reasons into 7 broader factors. We found that being a harmful spouse was the most important factor for divorce, followed by incompatibility and in-law problems. We also found significant sex differences in several factors such as women indicating a higher willingness than men to divorce a harmful spouse. In addition, participants with children were less willing to divorce a harmful spouse than those who had no children. Finally, using second-order principal components analysis, we classified the 7 factors into 2 broader domains of reasons for getting a divorce.     

Organizational Changes and Job Satisfaction among Support Staff

ABSTRACT

The purpose of this study is to identify job satisfaction amongst support staff employed by a nonprofit company undergoing organizational changes. The Job Satisfaction Survey (JSS) scale was used to measure overall job satisfaction and was conducted among 38 workers and the data was analyzed using content analysis. The findings indicate that workers were satisfied with some sections of their job but also dissatisfied with some others, scoring an average job satisfaction amongst the participating groups. Factors such as good relations with colleagues, training opportunities, and work flexibility were identified to assist with increasing worker satisfaction. Further suggestions for enhancing employees’ job satisfaction are provided.     

The use of GARCH models in VaR estimation

We evaluate the performance of an extensive family of ARCH models in modeling the daily Value-at-Risk (VaR) of perfectly diversified portfolios in five stock indices, using a number of distributional assumptions and sample sizes. We find, first, that leptokurtic distributions are able to produce better one-step-ahead VaR forecasts; second, the choice of sample size is important for the accuracy of the forecast, whereas the specification of the conditional mean is indifferent. Finally, the ARCH structure producing the most accurate forecasts is different for every portfolio and specific to each equity index.     

On the relation between Hodges-Lehmann efficiency and Pitman efficiency

The relation between Hodges–Lehmann efficiency and Pitman efficiency is studied in the context of testing one-sided hypotheses about a real-valued parameter. It is first shown that for tests based on sums of independently and identically distributed observations local Hodges-Lehmann efficiency is equivalent to Pitman efficiency. Then, it is proved that this equivalence also carries over to tests based on two broad classes of M -estimators for the location problem. In all cases considered explicit formulas of the Hodges-Lehmann efficacies are obtained.     

On a Simultaneous Characterization of the Poisson and Bernoulli Distributions

Kimeldorf et al. (1981) established a simultaneous characterization of the Poisson and Bernoulli distributions. In this note two variants of the authors' characterizing condition are considered each of which is shown also to characterize simultaneously the Poisson and Bernoulli distributions.     

Optimal Inattention to the Stock Market With Information Costs and Transactions Costs

Information costs, which comprise costs of gathering and processing information about stock values and costs of deciding how to respond to this information, induce a consumer to remain inattentive to the stock market for finite intervals of time. Whether, and how much, a consumer transfers assets between accounts depends on the costs of undertaking such transactions. In general, optimal behavior by a consumer facing both information costs and transactions costs is state‐dependent, with the timing of observations and the timing and size of transactions depending on the state. Surprisingly, if the fixed component of the transactions cost is sufficiently small, then eventually, with probability 1, a time‐dependent rule emerges: the interval between observations is constant and on each observation date, the consumer converts enough assets to liquid assets to finance consumption until the next observation. If the fixed component of transactions costs is large, the optimal rule remains state‐dependent indefinitely.     

Exploring Time Perspective in Greek Young Adults: Validation of the Zimbardo Time Perspective Inventory and Relationships with Mental Health Indicators

In this article we examine the factorial structure of the Greek version of the Zimbardo Time Perspective Inventory (ZTPI; Zimbardo and Boyd in J Personal Soc Psychol 77:1271–1288, 1999), in a sample of 337 university students, using principal axis factoring (PAF) with oblique rotation, and its dimensionality using parallel analysis. Moreover, we evaluate the internal consistency reliability, the convergent validity (through associations with mental health indicators such as dispositional optimism, self-esteem, trait anxiety, depression, and proactive coping), as well as discriminant, and differential validity of this instrument. The results indicated that the ZTPI had a 5-factor structure (past negative, past positive, present fatalistic, present hedonistic, future). Correlational analyses indicated that an aversive view of the past, and a fatalistic attitude toward life were positively and significantly associated with trait anxiety and depression, while they were negatively correlated with self-esteem, proactive coping, and dispositional optimism. Future time perspective was positively associated with proactive coping, whereas a positive attitude toward the past was negatively associated with depression and trait anxiety. Psychometric properties of the five ZTPI scales were satisfactory (Cronbach’s alphas ranging from .710 to .845), thus facilitating the robust investigation of time perspective in Greek speaking populations. However confirmatory factor analyses revealed that the “positive attitude toward the past” dimension might not be a good indicator of time perspective. We discuss the theoretical implications of these findings for future studies of time perspective.     

Prior distributions for variance parameters in a sparse-event meta-analysis of a few small trials

In rare diseases, typically only a small number of patients are available for a randomized clinical trial. Nevertheless, it is not uncommon that more than one study is performed to evaluate a (new) treatment. Scarcity of available evidence makes it particularly valuable to pool the data in a meta-analysis. When the primary outcome is binary, the small sample sizes increase the chance of observing zero events. The frequentist random-effects model is known to induce bias and to result in improper interval estimation of the overall treatment effect in a meta-analysis with zero events. Bayesian hierarchical modeling could be a promising alternative. Bayesian models are known for being sensitive to the choice of prior distributions for between-study variance (heterogeneity) in sparse settings. In a rare disease setting, only limited data will be available to base the prior on, therefore, robustness of estimation is desirable. We performed an extensive and diverse simulation study, aiming to provide practitioners with advice on the choice of a sufficiently robust prior distribution shape for the heterogeneity parameter. Our results show that priors that place some concentrated mass on small τ values but do not restrict the density for example, the Uniform(−10, 10) heterogeneity prior on the log(τ²) scale, show robust 95% coverage combined with less overestimation of the overall treatment effect, across varying degrees of heterogeneity. We illustrate the results with meta-analyzes of a few small trials.     

Stakeholder Communication in 140 Characters or Less: A Study of Community Sport Foundations

Community sport foundations (CSFs), like other non-profit organizations, are increasingly employing social media such as Twitter to communicate their mission and activities to their diverse stakeholder groups. However, the way these CSFs utilize social media for communicating such practices remains unclear. Through a mixed-method approach of content analysis of tweets from 22 CSFs established by English professional football clubs and interviews with key individuals within these CSFs (n = 7), this study examines the extent to which CSFs’ core activities are being communicated through Twitter and identifies the strategies employed for doing so. Reflecting the target audiences CSFs are seeking to reach through Twitter and the challenges associated with communication about projects involving marginalized groups, tweets largely concern programs related to sports participation and education. The most frequently employed communication strategy is to inform, rather than interact or engage with stakeholders. However, CSFs with higher organizational capacity attempt to go beyond mere informing towards engaging with stakeholder groups that relate to their social agenda, highlighting the importance of trained and dedicated social media personnel in optimizing CSFs’ use of Twitter for communication.