The residual life of the renewal process: A simple algorithm

We develop a simple algorithm, which does not require convolutions, for computing the distribution of the residual life when the renewal process is discrete. We also analyze the algorithm for the particular case of lattice distributions, and we show how it can apply to an inventory problem. © 1999 John Wiley & Sons, Inc. Naval Research Logistics 46: 435–443, 1999     

Defence and firm performance in the UK

The UK Ministry of Defence is British industry's largest single customer and a number of firms and industries are highly dependent on defence sales. Various hypotheses have been proposed about the impact of defence procurement on firms and these are investigated using four performance indicators: financial structure, investment, productivity and profitability. With regard to the borrowing ratio, capital investment and the rate of return, there is no statistically significant difference between the mean financial ratios for low and high dependence firms. However, non‐dependents appear to have a higher level and rate of growth of labour productivity than dependents.     

Property distribution and configurations of sovereign states: A rational economic model

A nation's wealth is both an object of conquest to covetous aggressors and a resource to its owners for self defense. To maintain autonomy every country must mount a defense which either makes its capture (1) more expensive than any aggressor can afford, or (2) more expensive than it is worth to aggressors. Whether this condition can be satisfied for all countries simultaneously depends as shown in this paper on relative efficacy of military offense versus defense, the aggregate of wealth among nations and its distribution, and the benefits a conqueror may obtain from conquest, including the duration of these benefits. The paper shows how these factors fit together to determine the sustainability and stability of the international distribution of property as embodied in the configuration of sovereign states.     

How old is too old? An economic approach to replacing military aircraft

The US Air Force is asking when to replace its aging aircraft. We develop a framework to identify economically optimal replacement strategies that recognizes cost trade-offs and incorporates age effects. We also preview a stochastic methodology. We use the framework to identify an optimal strategy, defined by the replacement age, for a generic fleet and conduct a sensitivity analysis. Quantitative illustrations show that the range of strategies that provides close-to-optimal outcomes widens as the operating and support (O&S) cost growth rate decreases and the ratio of the acquisition price to the initial O&S cost increases. A wider range implies more decision-making leeway.     

Assessing the role of the African Union in preventing and combating terrorism in Africa

The period after 9/11 can be characterised as the terrorism moment in world history. Every actor in international relations—the state, regional, continental and international as well as civil society organisations—has been mobilised to combat what, apparently has been conceived as a common security threat to humanity. The transformation of the Organisation of African Unity (OAU) into the African Union (AU) was a divine coincidence at a time when multilateralism and international cooperation were being challenged by the threat of terrorism. In the post-9/11 period, the main concern of the Union has been to reinforce and implement existing counter-terrorism instruments adopted at the continental level in coordination with states and regional organisations. This article discusses and appraises the endeavours undertaken by the AU and its precursor organisation, the OAU, in tackling and dealing with the threat of terrorism despite limitations to its human and financial resources. In recognition of the nature of the states in Africa and the challenges facing the Union, we argue that the role of the AU remains critical in order to fill the gaps where its member states or regional mechanisms are lacking. In this regard, we stress that the role of the AU should be complementary and serve as an interface between the continent and the international community, including the United Nations.