A Simulation of Partial Information Use in Decision Making: Implications for DSS Design

Information matrices are often the output produced by a decision support system. These matrices are a common method for expressing a decision situation under different decision-making scenarios. The decisions involved in designing a decision support system to generate the information matrix are important and involve several cost and benefit components. A designer needs guidance in making effective design decisions in this context. Such guidance can be provided by considering the relationships among specific design decisions, costs, and benefits. The general objective of this study is to provide a comprehensive framework for this purpose. This study is the first to develop and present a comprehensive cost-benefit framework for evaluating design decisions for a variety of scenarios. The specific objective of this research is to provide guidance regarding the number of available information dimensions to incorporate in a computer-based decision aid. Simulation experiments are conducted with a completely specified model based on the cost-benefit framework (including needed assumptions) to evaluate how many information dimensions to include for a specific information matrix size to achieve a balance between information use costs and decision quality. Based upon extensive simulation analyses for a hypothetical decision maker, the practical guideline found for designers is to include only the top half of the relevant information dimensions in any specific decision support system. Over a large number of repeating choice decisions, the savings in cognitive effort and information gathering costs clearly offset relatively minor losses in decision quality.     

Relationship between boardroom independence and corporate performance: Reflections and perspectives

The perceived economic value of an independent boardroom configuration has progressively emerged as a matter of considerable importance in the academic and popular literature. The normative research paradigm has fundamentally been dominated by positivists who formulate inferential models populated by large sets of archival data. Regrettably, however, several decades of intense inquiries and passionate debates have invariably failed to ascertain (or dispel) the economic value of an independent boardroom configuration. The lingering boardroom independence–corporate performance saga has reached an impasse with no clear resolution in the foreseeable future. In this study, I provide a diagnosis (through the thematic analysis of semi-structured interviews) of why the economic viability of an independent boardroom remains an elusive phenomenon for positivist researchers. A central reason for the research impasse is attributed to ontological complexities intrinsic to the very nature of the corporation, compounded by multiple layers of methodological complexities. Ultimately, the disentanglement of this enigma would require a pivotal reconceptualization of the corporate governance research agenda.     

Multiple cases deletion measures in linear measurement error models

In this paper, we define a multiple cases deletion model (MCDM) in linear measurement error models (LMEMs). Then, by using the corrected score method of Nakamura (1990), the estimation of parameters is obtained. Furthermore, Based on MCDM, we provide computationally inexpensive deletion diagnostic tools for LMEMs. An example illustrates that our method is useful for diagnosing influential subsets of observations.     

Key considerations for choosing a statistical method to deal with incomplete treatment adherence in pragmatic trials

Pragmatic trials offer practical means of obtaining real-world evidence to help improve decision-making in comparative effectiveness settings. Unfortunately, incomplete adherence is a common problem in pragmatic trials. The commonly used methods in randomized control trials often cannot handle the added complexity imposed by incomplete adherence, resulting in biased estimates. Several naive methods and advanced causal inference methods (e.g., inverse probability weighting and instrumental variable-based approaches) have been used in the literature to deal with incomplete adherence. Practitioners and applied researchers are often confused about which method to consider under a given setting. This current work is aimed to review commonly used statistical methods to deal with non-adherence along with their key assumptions, advantages, and limitations, with a particular focus on pragmatic trials. We have listed the applicable settings for these methods and provided a summary of available software. All methods were applied to two hypothetical datasets to demonstrate how these methods perform in a given scenario, along with the R codes. The key considerations include the type of intervention strategy (point treatment settings, where treatment is administered only once versus sustained treatment settings, where treatment has to be continued over time) and availability of data (e.g., the extent of measured or unmeasured covariates that are associated with adherence, dependent confounding impacted by past treatment, and potential violation of assumptions). This study will guide practitioners and applied researchers to use the appropriate statistical method to address incomplete adherence in pragmatic trial settings for both the point and sustained treatment strategies.     

Sex Selection for Daughters: Demographic Consequences of Female-Biased Sex Ratios

Population Research and Policy Review - Modern fertility techniques allow parents to carry out preimplantation sex selection. Sex selection for non-medical purposes is legal in many high-income...     

Identification and Identification Failure for Treatment Effects Using Structural Systems

We provide necessary and sufficient conditions for effect identification, thereby characterizing the limits to identification. Our results link the nonstructural potential outcome framework for identifying and estimating treatment effects to structural approaches in economics. This permits economic theory to be built into treatment effect methods. We elucidate the sources and consequences of identification failure by examining the biases arising when the necessary conditions fail, and we clarify the relations between unconfoundedness, conditional exogeneity, and the necessary and sufficient identification conditions. A new quantity, the exogeneity score, plays a central role in this analysis, permitting an omitted variable representation for effect biases. This analysis also provides practical guidance for selecting covariates and insight into the price paid for making various identifying assumptions and the benefits gained.     

Financial Contracting,Governance Structures and the Accounting Regulation of Islamic Banks: An Analysis in Terms of Agency Theory and Transaction Cost Economics

Because Islamic banks are prohibited from entering into transactions based on riba (interest), they mobilise funds mainly on the basis of the mudaraba (profit-sharing) form of contract. Thus, in the place of interest-bearing customer deposits, Islamic banks offer investment accounts the return on which depends on the return on the pool of assets in which the customers' funds are invested by the bank. In contrast to conventional deposits, such investment accounts therefore yield a variable periodic return which may be negative (a loss). Islamic investment accounts are thus a form of limited-duration equity investment.This type of investment account raises a set of issues concerning the contractual relations between the bank and the holders of such investment accounts. These issues may be addressed from the perspectives of both Agency Theory (principal-agent and principal-principal relations) and Transaction Cost Economics (contractual forms and governance structures), and it is the purpose of this paper to do so. In particular, we focus on governance issues such as the monitoring possibilities which may or may not be contractually available to investment account holders. We conclude that, under present contractual arrangements, investment account holders depend unduly upon 'vicarious' monitoring by or on behalf of shareholders, a situation aggravated by current shortcomings in financial reporting and limitations of the scope of external auditing. The latter have implications for accounting regulation as applied to Islamic banks. The paper concludes with some suggestions as to how this situation could be ameliorated.     

Approximation and sampling of multivariate probability distributions in the tensor train decomposition

Statistics and Computing - General multivariate distributions are notoriously expensive to sample from, particularly the high-dimensional posterior distributions in PDE-constrained inverse...     

Estimation of variance components in linear mixed measurement error models

In this paper, we consider a linear mixed model with measurement errors in fixed effects. We find the corrected score function estimators for the variance components. An iterative algorithm is proposed for estimating the parameters. The computations on each iteration of this algorithm are those associated with computing estimates of fixed and random effects for given values of the variance components. We also derive the consistency of the estimators under regularity conditions. The simulation study shows that for relatively small sample size the corrected estimators perform very well. Finally, an example of real data is given for illustration.     

Ethical Challenges in International HIV Prevention Research

Members of an HIV-prevention research network were asked to describe ethical challenges faced in their work. Major themes included acceptable standards of care for participants, defining research of relevance to host countries, reducing risks related to stigma, designing research that meets local needs without contributing to an inadequate status quo, and ensuring informed consent for complex research with potentially vulnerable participants. The challenges are interrelated and highlight the need for innovative, practical strategies to be incorporated into the planning, design, and conduct of HIV prevention trials. Research in applied ethics to support decision-making about HIV prevention research is needed, along with ethics training, mechanisms to support community-wide benefit from research, and expanded dialog on the ethics surrounding HIV prevention and public health research.