Constant risk aversion in stochastic contests with exponential completion times

This article analyzes a class of stochastic contests among multiple players under risk‐averse exponential utility. In these contests, players compete over the completion of a task by simultaneously deciding on their investment, which determines how fast they complete the task. The completion time of the task for each player is assumed to be an exponentially distributed random variable with rate linear in the player's investment and the completion times of different players are assumed to be stochastically independent. The player that completes the task first earns a prize whereas the remaining players earn nothing. The article establishes a one‐to‐one correspondence between the Nash equilibrium of this contest with respect to risk‐averse exponential utilities and the nonnegative solution of a nonlinear equation. Using the properties of the latter, it proves the existence and the uniqueness of the Nash equilibrium, and provides an efficient method to compute it. It exploits the resulting representation of the equilibrium investments to determine the effects of risk aversion and the differences between the outcome of the Nash equilibrium and that of a centralized version.© 2016 Wiley Periodicals, Inc. Naval Research Logistics 66:4–14, 2019     

Some new results on the preservation of the NBUE and NWUE aging classes under the formation of coherent systems

We consider the classical problem of whether certain classes of lifetime distributions are preserved under the formation of coherent systems. Under the assumption of independent and identically distributed (i.i.d.) component lifetimes, we consider the NBUE (new better than used in expectation) and NWUE (new worse than used in expectation) classes. First, a necessary condition for a coherent system to preserve the NBUE class is given. Sufficient conditions are then obtained for systems satisfying this necessary condition. The sufficient conditions are satisfied for a collection of systems which includes all parallel systems, but the collection is shown to be strictly larger. We also prove that no coherent system preserves the NWUE class. As byproducts of our study, we obtain the following results for the case of i.i.d. component lifetimes: (a) the DFR (decreasing failure rate) class is preserved by no coherent systems other than series systems, and (b) the IMRL (increasing mean residual life) class is not preserved by any coherent systems. Generalizations to the case of dependent component lifetimes are briefly discussed.     

On gamma estimation via matrix kriging

In financial engineering, sensitivities of derivative prices (also known as the Greeks) are important quantities in risk management, and stochastic gradient estimation methods are used to estimate them given the market parameters. In practice, the surface (function) of the Greeks with respect to the underlying parameters is much more desired, because it can be used in real‐time risk management. In this paper, we consider derivatives with multiple underlying assets, and propose three stochastic kriging‐based methods, the element‐by‐element, the importance mapping, and the Cholesky decomposition, to fit the surface of the gamma matrix that can fulfill the time constraint and the precision requirement in real‐time risk management. Numerical experiments are provided to illustrate the effectiveness of the proposed methods.     

A conceptual framework for the analysis of civil-military relations and intelligence

ABSTRACT

The article argues that current conceptual approaches in civil-military relations are deeply flawed resulting in its irrelevance in analyzing major issues including war and the collapse of democracy. After highlighting major flaws in the work of the late Samuel Huntington and those who follow his approach, the article argues that other conceptual approaches, including Security Sector Reform, are also flawed, or in the case of the “military effectiveness” literature, largely irrelevant. In explaining the main causes of the flawed conceptual literature, the article highlights the absence of good data and challenges in methodology. While arguing that military forces are very unlikely to engage in armed combat, it highlights the roles and missions which in the world today are implanted by these forces. As it is virtually impossible to prove effectiveness of the armed forces in these roles and missions, the article proposes a conceptual approach based on requirements.     

Intellectual spring cleaning: it’s time for a military “Do Not Read” list; and some sources that should be on that list

Military reading lists, intended to promote professional reading and in turn enhance education and develop critical thinking skills and sound judgement, recommend key texts to military personnel. This is a noble intent but the lists themselves, while generally good, are not flawless. Critiques of military reading lists often focus on what sources they are missing. This article offers its own critique but from a different perspective. It does so by analysing why some sources, which have become outdated, are based on faulty or incomplete research, have been thoroughly disproven, or some combination of the above, nevertheless linger on military reading lists. It then offers a short list of such sources, which it recommends be either removed from existing reading lists or accompanied by other sources that place the original source in appropriate historical context. Where applicable, it also recommends alternative sources that provide insights into the same subject matter. In so doing, this article is intended generate debate and to assist militaries to achieve a better balance between evaluation, induction and retention of valid knowledge on one hand, and rejection of outdated or flawed knowledge on the other.     

Uncultured: Civil War and Cultural Policy

How does cultural policy affect violence? While cultural discrimination is frequently cited as a potential grievance motivating political violence, the relationship remains under-theorised and largely untested. I weave theoretical literatures with interviews and secondary sources on the experience of Kurds in Turkey to understand the socio-economic and psychological pathways through which cultural policies impact intrastate conflict. I then analyse cross-national data on political violence, demonstrating that cultural grievances increase support for violence, raise the chance and severity of conflict and prolong violent conflicts. In short, policy matters: cultural restrictions exacerbate violence through multiple pathways.     

Security,structural factors and sovereignty: Analysing reactions to Kenya’s decision to close the Dadaab refugee camp complex

Kenya’s decision to close the Dadaab refugee camp complex highlights structural flaws in the international refugee regime. While much attention has been paid to Kenya’s reasoning, less has been given to the reactions of organisations and states. Given the state’s primacy in the international system and uncertainty about refugees, Kenya’s decision is perhaps unsurprising. It is contended that the stakeholders were unprepared because of path dependence and disbelief that Kenya would repatriate the refugees. While stakeholder reactions arguably demonstrate concern for refugees, the international refugee regime remains unquestioned, sustaining revenue streams that may fuel corruption, encourage lengthy encampment and prolong conflict.     

Unsolved murders and the investigative failures of the Nigerian police force: Security and sociopolitical implications

This article focuses on the systemic failures of the Nigerian police force to unravel the mysteries surrounding homicides in the country, along with the security, social and political implications of the ongoing trend. The article draws on documented pieces of evidence of high-profile murders, along with the causes of the upsurge in murder incidences and the inhibitive factors relating to the investigative procedures of the police. The suitability of the theory of subaltern realism and the concept of third-world security predicaments in explaining the peculiarities of Nigeria’s internal security challenges is examined, along with the problems of the legitimacy of political regimes and weak borders. There is a need for the National Assembly of Nigeria to exercise its constituted powers in reawakening and supervising investigations into dormant cases of murder through its committees on police affairs, public safety and national security. The police should check its organisational failures, which may be related to using the wrong investigative approaches, low levels of information, limited resources, corrupt practices, and pressure to obtain quick results.     

Safety in international security: a view point from the practice of accident investigation

While security points to a deliberate harming of humans and/or the environment, safety refers to unintended damage. In this view point, I will analyse how the distinction between safety and security matters in the practice of accident investigation and I will argue that the division between the fields is problematic for the assessment of security-related safety risks. Drawing on the case of the our accident investigation into the downing of flight MH17 above Ukraine in 2014, I highlight key dilemmas the Dutch Safety Board dealt with.     

Resilience in peacebuilding: Contesting uncertainty,ambiguity, and complexity

With the failure of liberal peace strategies in the Global South, resilience has recently become the risk management strategy par excellence in peacebuilding. Since it is not possible to predict when the next crisis will take place, peacebuilders must invest in bottom-up adaptive capacities to cope with external shocks. This article moves away from governmentality accounts of resilience which are overtly deterministic and depoliticizing. Instead, it posits that the uncertainty, ambiguity, and complexity associated with resilience mean that we should expect opportunities for contestation and institutional agency. This argument will be illustrated by drawing upon the European Union’s adoption of the resilience approach in its peacebuilding and security policies. The article argues that while uncertainty, ambiguity, and complexity constitute the ontological conditions that underpin the rise of resilience in peacebuilding, they are also likely to lead to its potential demise.