Estimation of the cumulative incidence function under multiple dependent and independent censoring mechanisms

Competing risks occur in a time-to-event analysis in which a patient can experience one of several types of events. Traditional methods for handling competing risks data presuppose one censoring process, which is assumed to be independent. In a controlled clinical trial, censoring can occur for several reasons: some independent, others dependent. We propose an estimator of the cumulative incidence function in the presence of both independent and dependent censoring mechanisms. We rely on semi-parametric theory to derive an augmented inverse probability of censoring weighted (AIPCW) estimator. We demonstrate the efficiency gained when using the AIPCW estimator compared to a non-augmented estimator via simulations. We then apply our method to evaluate the safety and efficacy of three anti-HIV regimens in a randomized trial conducted by the AIDS Clinical Trial Group, ACTG A5095.     

Development of predictive signatures for treatment selection in precision medicine with survival outcomes

For survival endpoints in subgroup selection, a score conversion model is often used to convert the set of biomarkers for each patient into a univariate score and using the median of the univariate scores to divide the patients into biomarker‐positive and biomarker‐negative subgroups. However, this may lead to bias in patient subgroup identification regarding the 2 issues: (1) treatment is equally effective for all patients and/or there is no subgroup difference; (2) the median value of the univariate scores as a cutoff may be inappropriate if the sizes of the 2 subgroups are differ substantially. We utilize a univariate composite score method to convert the set of patient's candidate biomarkers to a univariate response score. We propose applying the likelihood ratio test (LRT) to assess homogeneity of the sampled patients to address the first issue. In the context of identification of the subgroup of responders in adaptive design to demonstrate improvement of treatment efficacy (adaptive power), we suggest that subgroup selection is carried out if the LRT is significant. For the second issue, we utilize a likelihood‐based change‐point algorithm to find an optimal cutoff. Our simulation study shows that type I error generally is controlled, while the overall adaptive power to detect treatment effects sacrifices approximately 4.5% for the simulation designs considered by performing the LRT; furthermore, the change‐point algorithm outperforms the median cutoff considerably when the subgroup sizes differ substantially.     

Discussion of “Nonparametric Bayesian Inference in Applications”: Bayesian nonparametric methods in econometrics

The use of Bayesian nonparametrics models has increased rapidly over the last few decades driven by increasing computational power and the development of efficient Markov chain Monte Carlo algorithms. We review some applications of these models in economic applications including: volatility modelling (using both stochastic volatility models and GARCH-type models) with Dirichlet process mixture models, uses in portfolio allocation problems, long memory models with flexible forms of time-dependence, flexible extension of the dynamic Nelson-Siegel model for interest rate yields and multivariate time series models used in macroeconometrics.     

A penalized likelihood method for nonseparable space–time generalized additive models

In this paper, we study space–time generalized additive models. We apply the penalyzed likelihood method to fit generalized additive models (GAMs) for nonseparable spatio-temporal correlated data in order to improve the estimation of the response and smooth terms of GAMs. The results show that our space–time generalized additive models estimated response and smooth terms reasonable well, and in addition, the mean squared error, mean absolute deviation and coverage intervals improved considerably compared to the classic GAM. An application on particulate matter concentration in the North-Italian region of Piemonte is also presented.     

Control or Autonomy? A Case Study of two Organizational Forms in the Zhangjiakou Internal Migrant Organization

Control often weakens autonomy in organizational theories. While many scholars focus on the paradox of control and autonomy, few pay attention to how an organization obtains both control and autonomy. By exploring Zhangjiakou Internal Immigrant Organization, this study finds two mechanisms can contribute to the balanced combination of control and autonomy. First, managers play ambidextrous official-merchant roles, which means superiors take both bureaucratic and autonomous management styles. Second, members have dual organizational goals for both political status and network support. In conclusion, the successful combination is shaped by the subjective interaction between the government, superior managers and subordinate members.     

Yes Academic Bias is a Problem and We Need to Address it: a Response to Larregue

Larregue argued that while there is an ideological imbalance among academics that this imbalance has not unfairly impacted our findings. He also implies that it is the activism of conservatives, rather than progressives, which has created real problems in academia. As such he disputes claims that activism among progressive academics has create a backlash from political conservatives. However, Larregue does not address the previous empirical work on the subject of academic bias. Furthermore, his argument of methodological rigor does not address the tendency of scholars to overlook alternate theories. His argument that progressive scholars are no more biased than conservative scholars fails to account for the sheer number of progressive scholars relative to conservative scholars as it concerns the possibly of institutional bias. I also find his focus on fraud to be misplaced since scholars do not have to engage in fraud to be in ideological silos that do not take alternative theories into account. As to his second major argument, I am unsure whether liberal academic activism leads to conservative mistrust and await further future research on this topic. I do commend Larregue in bringing the question of sources of conservative mistust to our attention.     

What makes hybrid insourcing successful: A new public–private partnership model for social welfare services

Outsourcing has been a key policy tool for delivering a range of social services, and regarded as more effective than insourcing or direct government provision. At the same time, it has also caused many delivery issues such as principal‐agent problems, a lack of policy coordination, and poor‐quality welfare services. While the pendulum continues to swing between insourcing and outsourcing, we aim to propose a new public–private partnership model called the “hybrid insourcing model” and examine which factors influence the performance of the model. In South Korea, around 2010, the local government in Namyangju City was the first to implement the “Hope Care Center model,” a kind of hybrid insourcing model, which has been praised for its innovation and widely emulated by central and local governments. Our analysis utilizes data collected between December 2017 and January 2018 from public sector employees and civilian staff in Namyangju and a comparable city, A. From this, we draw a number of implications, both for theory and for policy. We argue that, for public–private partnerships, active cooperation and equality are the biggest factors in contributing to positive performance. These work alongside leaders with a clear vision and with employees' positive attitude.     

Learning from others: conditioning versus averaging

How should we revise our beliefs in response to the expressed probabilistic opinions of experts on some proposition when these experts are in disagreement? In this paper I examine the suggestion that in such circumstances we should adopt a linear average of the experts’ opinions and consider whether such a belief revision policy is compatible with Bayesian conditionalisation. By looking at situations in which full or partial deference to the expressed opinions of others is required by Bayesianism I show that only in trivial circumstances are the requirements imposed by linear averaging compatible with it.     

Funding Civil Society? Bilateral Government Support for Development NGOs

Research on the determinants of foreign aid tends to focus on the relationship between donor country priorities and recipient state characteristics, but donors also make decisions about which organizations and programs within countries will receive assistance. Although NGOs increasingly have been recipients of foreign aid, few data are available to investigate which organizations within a given country receive that funding. Donors may prioritize structural characteristics of NGOs or their local ties—or they may seek a combination that blends concern about efficiency and accountability with an interest in developing national civil society. We use original data from Cambodia to explore whether aid is likely to go to managerial organizations (professionalized NGOs and NGOs that utilize modern management tools) or to organizations that are embedded in the domestic context. We argue that managerialism provides legitimacy for NGOs by signaling capacity and accountability to donors, increasing the likelihood of government funding. We argue that local embeddedness also confers legitimacy by aligning community ties and networks to rights-based development, increasing the likelihood of government funding. We find general support for the managerialism argument, but donor agencies do not prioritize direct funding for “indigenous” NGOs—not even among those with high levels of managerialism.     

Relational Management Mechanisms for Strategic Alliances Among Nonprofit Organizations

This study employs a qualitative multiple-case study to explore relational management mechanisms for strategic nonprofit alliances (NPAs) formed by at least 3 nonprofit organizations by examining collaborative relationships among farmers associations in Taiwan. We explore these mechanisms by analyzing case data from four strategic cooperation characteristics, which can best explain NPAs. To effectively sustain partnerships, our findings suggest that an NPA applies acceptable collaborative rules and regulations, common standard procedures, symmetric information and communication, and capability building and corrective measures when cooperation involves high input commonality. The results also suggest empowerment for partners with deeper input commitment to direct decisions on resource distribution and utilization when collaborative ties involve low input measurability. Regarding high output commonality, we advise NPAs to enforce common output quality control, efficient substandard-output treatment, and external incentives as mechanisms to encourage partners for continued commitment. If relationships involve low output measurability, our findings suggest that NPAs heighten partners’ voluntary motivation for the common good, with goal-achievement assessment measures, professional certification by external experts, and acceptable and reasonable benefit-sharing methods