Subsea Release of Oil from a Riser: An Ecological Risk Assessment

This study illustrates a newly developed methodology, as a part of the U.S. EPA ecological risk assessment (ERA) framework, to predict exposure concentrations in a marine environment due to underwater release of oil and gas. It combines the hydrodynamics of underwater blowout, weathering algorithms, and multimedia fate and transport to measure the exposure concentration. Naphthalene and methane are used as surrogate compounds for oil and gas, respectively. Uncertainties are accounted for in multimedia input parameters in the analysis. The 95th percentile of the exposure concentration (EC_95%) is taken as the representative exposure concentration for the risk estimation. A bootstrapping method is utilized to characterize EC_95% and associated uncertainty. The toxicity data of 19 species available in the literature are used to calculate the 5th percentile of the predicted no observed effect concentration (PNEC_5%) by employing the bootstrapping method. The risk is characterized by transforming the risk quotient (RQ), which is the ratio of EC_95% to PNEC_5%, into a cumulative risk distribution. This article describes a probabilistic basis for the ERA, which is essential from risk management and decision‐making viewpoints. Two case studies of underwater oil and gas mixture release, and oil release with no gaseous mixture are used to show the systematic implementation of the methodology, elements of ERA, and the probabilistic method in assessing and characterizing the risk.     

Impacts of Demographics on Citizen's Access to Information: An Empirical Study of District Dera Ismail Khan, North Western Frontier Province, Pakistan

The impact of demographic dimensions on local government behavior is well identified, analyzed and documented at the global level. Likewise, several studies are available on developing countries, but empirical evidence on the conditions of Pakistan is lacking. This study is an effort to unearth empirical evidence on access to information in the local government system exemplifying data from the district Dera Ismail Khan (DIK), North Western Frontier Province (NWFP). Most global hypotheses for developing countries are accepted in this study but the statistics on local data are far more different in terms of the value and weight of variables, relationships and impacts on the research concepts. The most dominant concept in the impact of access to information on the local government system is education for all. Mass education is a leading concept in making or breaking the role of people participation in the success or failure of local democracies. Data show that illiteracy is causing many problems, including the mass population's unawareness of their interests and duties at the public level, thereby giving the ruling elite a free hand in exploiting public resources for self-interest, at the cost of the public good.     

Risk Management of Domino Effects Considering Dynamic Consequence Analysis

Domino effects are low‐probability high‐consequence accidents causing severe damage to humans, process plants, and the environment. Because domino effects affect large areas and are difficult to control, preventive safety measures have been given priority over mitigative measures. As a result, safety distances and safety inventories have been used as preventive safety measures to reduce the escalation probability of domino effects. However, these safety measures are usually designed considering static accident scenarios. In this study, we show that compared to a static worst‐case accident analysis, a dynamic consequence analysis provides a more rational approach for risk assessment and management of domino effects. This study also presents the application of Bayesian networks and conflict analysis to risk‐based allocation of chemical inventories to minimize the consequences and thus to reduce the escalation probability. It emphasizes the risk management of chemical inventories as an inherent safety measure, particularly in existing process plants where the applicability of other safety measures such as safety distances is limited.     

A case study on a generalist service delivery model for street children in Durban,South Africa: Insights from the capability approach

This paper adopts a qualitative case study on the generalist service delivery model of I‐Care, a Durban‐based non‐governmental organization that works with male street children. Fifteen face‐to‐face interviews were conducted with 10 I‐Care employees and 5 former street children. A focus group was set up with I‐Care employees. Although existing literature is forthright about a generalist approach for children at risk, it remains unclear how to implement this approach in practice. This paper reviews a continuity of 5 fundamental social work practices for working with street children: (a) outreach work, (b) child–family and child–community mediation, (c) transitory care centres and programmes, (d) brokerage, and (e) mentorship and follow‐ups. The study analyses how these practices contribute to the capability and agency expansion of the street children and outlines challenges that service providers and former street children experience. The main challenges acknowledged are balancing between the agency and protection of street children and the adaptation of children to street life. The study proposes intervention strategies to overcome these challenges.     

Exponentiated Weibull regression for time-to-event data

The Weibull, log-logistic and log-normal distributions are extensively used to model time-to-event data. The Weibull family accommodates only monotone hazard rates, whereas the log-logistic and log-normal are widely used to model unimodal hazard functions. The increasing availability of lifetime data with a wide range of characteristics motivate us to develop more flexible models that accommodate both monotone and nonmonotone hazard functions. One such model is the exponentiated Weibull distribution which not only accommodates monotone hazard functions but also allows for unimodal and bathtub shape hazard rates. This distribution has demonstrated considerable potential in univariate analysis of time-to-event data. However, the primary focus of many studies is rather on understanding the relationship between the time to the occurrence of an event and one or more covariates. This leads to a consideration of regression models that can be formulated in different ways in survival analysis. One such strategy involves formulating models for the accelerated failure time family of distributions. The most commonly used distributions serving this purpose are the Weibull, log-logistic and log-normal distributions. In this study, we show that the exponentiated Weibull distribution is closed under the accelerated failure time family. We then formulate a regression model based on the exponentiated Weibull distribution, and develop large sample theory for statistical inference. We also describe a Bayesian approach for inference. Two comparative studies based on real and simulated data sets reveal that the exponentiated Weibull regression can be valuable in adequately describing different types of time-to-event data.     

Discussion of “Simple Estimators for Invertible Index Models” by H. Ahn,H. Ichimura,J. Powell,and P. Ruud

This is an interesting article that considers the question of inference on unknown linear index coefficients in a general class of models where reduced form parameters are invertible function of one or more linear index. Interpretable sufficient conditions such as monotonicity and or smoothness for the invertibility condition are provided. The results generalize some work in the previous literature by allowing the number of reduced form parameters to exceed the number of indices. The identification and estimation expand on the approach taken in previous work by the authors. Examples include Ahn, Powell, and Ichimura (2004 Ahn, H., Powell, J., and Ichimura, H. (2004), “Simple Estimators for Monotone Index Models,” UC Berkeley Working Paper. [Google Scholar]) for monotone single-index regression models to a multi-index setting and extended by Blundell and Powell (2004 Blundell, R. W., and Powell, J. L. (2004), “Endogeneity in Semiparametric Binary Response Models,” The Review of Economic Studies, 71, 655–679.[Crossref], [Web of Science ®] , [Google Scholar]) and Powell and Ruud (2008 Powell, J., and Ruud, P. (2008), “Simple Estimators for Semiparametric Multinomial Choice Models,” UC Berkeley Working Paper. [Google Scholar]) to models with endogenous regressors and multinomial response, respectively. A key property of the inference approach taken is that the estimator of the unknown index coefficients (up to scale) is computationally simple to obtain (relative to other estimators in the literature) in that it is closed form. Specifically, unifying an approach for all models considered in this article, the authors propose an estimator, which is the eigenvector of a matrix (defined in terms of a preliminary estimator of the reduced form parameters) corresponding to its smallest eigenvalue. Under suitable conditions, the proposed estimator is shown to be root-n-consistent and asymptotically normal.     

Overcoming institutional voids as a pathway to becoming ambidextrous: The case of China's Sichuan Telecom

The paper examines how firms develop supply chain financing model to help overcome institutional voids (IVs) and become ambidextrous. This study presents a case analysis of a novel supply chain financing model instigated and implemented by China's Sichuan Telecom (ST) to help supply chain partners overcome IVs in their environments. We identified three unique stages in the evolution of the supply chain ambidextrous financing model: drivers for change (including identifying suppliers' problems and constraints), designing and implementing the supply chain ambidextrous financing model, and the tripartite performance effects. The analysis demonstrated how ST utilized its market power, resources and network ties to harness expertise and competences of small and medium-sized enterprises (SMEs) to overcome IVs and become ambidextrous. Sichuan Telecom aided the SMEs in solving the financing problem through order-based supply chain financing. Based on the analysis, we outline implications of this case for theory and policy.     

Connecting the Dots: Do Financial Analysts Help Corporate Boards Improve Corporate Social Responsibility?

This paper presents an examination of the joint impact of board structural elements at firm level and financial analysts as market-level corporate governance (CG) on corporate social responsibility (CSR) performance. Our study contributes to the CG–CSR literature by adopting the bundling approach, a perspective that has recently attracted researchers’ attention as an answer to any heterogeneity and fragmentation in existing findings. It is based on an extensive sample consisting of 7,739 firm-year observations of US firms for the 2006–2015 period. The findings suggest that financial analysts complement the corporate board with more independence, gender diversity and a specialized CSR committee to realize a certain level of CSR performance of a firm. The findings also indicate that analysts substitute for those internal governance factors that are associated with weaker boards – larger sizes and dual-role CEOs. We also draw implications for research and practice from our findings.     

Inference about the parameters of a bi-variate simultaneous equation model: structural approach

The paper considers a system of bi-linear responses having a regression structure with known predetermined variables. In econometric studies, the model is widely used and is known as simultaneous equation model. The probability distribution for the coefficients of the exogenous variables as well as that of the error variances along with the marginal likelihood function of the coefficients of the endogenous variables have been derived. The model in this paper has been analysed in the framework of a conditional structural model (Fraser 1968, 1979), which provides the basis of inference about all the parameters.     

The foster care system in India

The author has undertaken the difficult task of giving us an overall view of the foster care picture of all India, the first such panorama we have received.