Robust preallocated preferential defense

The problem is to protect a set of T identical targets that may come under attack by A identical weapons. The targets are to be defended by D identical interceptors, which must be preallocated to defend selected targets. The attacker is aware of the number of interceptors, but is ignorant of their allocation. The size of the attack is chosen by the attacker from within a specified range. The robust strategies developed in this article do not require the defender to assume an attack size. Rather, the defender chooses a strategy which is good over a wide range of attack sizes, though not necessarily best for any particular attack size. The attacker, knowing that the defender is adopting a robust strategy, chooses the optimal attack strategy for the number of weapons he chooses to expend. The expected number of survivors is a function of the robust defense strategy and optimal attack strategy against this robust defense.     

The Imperfect Peace: Explaining Paramilitary Violence in Northern Ireland

This article examines why paramilitary campaigns in Northern Ireland have continued despite the current peace process. In advancing three instrumental explanations of paramilitary violence, the author provides a useful analytical framework which shows that while organizational interpretations are dominating the public discourse, republicans and loyalists continue to use paramilitary violence as a strategic means of threat and coercion. Furthermore, even though policy implications are not discussed in detail, it will be demonstrated that the dominance of organizational imperatives has resulted in excessive leniency by the state, which - in turn - has contributed to the fragility of the peace process.     

Risk pooling in a two-period,two-echelon inventory stocking and allocation problem

The object of this article is to investigate the risk-pooling effect of depot stock in two-echelon distribution system in which the depot serves n retailers in parallel, and to develop computationally tractable optimization procedures for such systems. The depot manager has complete information about stock levels and there are two opportunities to allocate stock to the retailers within each order cycle. We identify first- and second-order aspects to the risk-pooling effect. In particular, the second-order effect is the property that the minimum stock available to any retailer after the second allocation converges in probability to a constant as the number of retailers in the system increases, assuming independence of the demands. This property is exploited in the development of efficient procedures to determine near-optimal values of the policy parameters.     

The optimal linear combination of control variates in the presence of asymptotically negligible bias

The optimal linear combination of control variates is well known when the controls are assumed to be unbiased. We derive here the optimal linear combination of controls in the situation where asymptotically negligible bias is present. The small-sample linear control which minimizes the mean square error (MSE) is derived. When the optimal asymptotic linear control is used rather than the optimal small-sample control, the degradation in MSE is c/n³, where n is the sample size and c is a known constant. This analysis is particulary relevant to the small-sample theory for control variates as applied to the steady-state estimation problem. Results for the method of multiple estimates are also given.     

Military spending and economic growth in South Africa

This paper undertakes an empirical analysis of the economic effects of military spending on the South African economy. It estimates a neo‐classical model common in the literature at the level of the macroeconomy and at the level of the manufacturing sector. An attempt is made to improve upon the model by allowing the data to determine the dynamic structure of the model through an ARDL procedure. No significant impact of military spending is found in aggregate, but there is a significant negative impact for the manufacturing sector. This suggests that the cuts in domestic military procurement that have occurred since 1989 could lead to improved economic performance in South Africa through their impact on the manufacturing sector.     

Reliability interpretations of some concepts from economics

In a recent article, Chandra and Singpurwalla have pointed out the close relationship between the Lorenz curve, which is frequently used when illustrating income distributions in economics, and the total-time-on-test transform (TTT transform), which has proved to be a very useful tool in reliability. They also presented some characterizations of aging properties by using the Lorenz curve. The purpose of this article is to point out some further results in the same area and to give reliability interpretations of some common measures of income inequality.