A dynamic nonlinear constrained optimal replacement model

A stochastically constrained optimal replacement model for capital equipment is constructed. Each piece of capital equipment, or machine, is characterized by its age and “utility” or “readiness” class. The readiness of a machine at any age is a stochastic function of its initial utility class and its age. The total discounted replacement cost of several replacement streams, each commencing with an initial machine, is minimized with respect to the replacement age and initial utility class of each machine, subject to a readiness constraint stating the lower bound on the expected number of machines in each utility class at any time. A general solution procedure is outlined and a specific case is solved in detail.     

Book reviews

European Security in the New Political Environment by James H. Wyllie, London: Addison, Wesley Longman, 1997, ISBN 0-582-24403-X (pbk), £13.99

Russia and Europe: The Emerging Security Agenda edited by Vladimir Baranovsky, Oxford: Oxford University Press, SIPRI, 1997, ISBN 0-19-829201-5 (hbk), £45.00

The Defeat of Japan by David Rees, Westport, Connecticut and London: Praeger, ISBN 0-275-95955-4 (hbk), £46.50

The Collective Naval Defence of the Empire, 1900-1940 by Nicholas Tracy (ed.), London: Ashgate, for the Navy Records Society, 1997, ISBN 1859-284-027 (hbk), £59.50

Knights in White Armour The New Art of War and Peace by Christopher Bellamy, London: Pimlico Press, 1997, ISBN 0-7126-739-03 (pbk), £12.50

Regional Orders: Building Security in a New World by avid A. Lake and Patrick M. Morgan (eds), University Park: Penn State Press, 1997, ISBN 0-271-01703-i (hbk), £49.50/$55, ISBN 0-271-01704-X (pbk), £7.95/$19.95

Contested Social Orders and International Politics by David Skidmore (ed.), Nashville: Vanderbilt University Press, 1997, ISBN 0-8265-1284-4 (hbk), $32.95

The Politics of Threat: Minuteman Vulnerability in American National Security Policy by David H. Dunn. London: Macmillan Press, 1997, ISBN 0-333-67816-8 (hbk), £45.00

The Sociology of the Military by Guiseppe Caforio (ed.), Cheltenham: Edward Elgar, 1998, ISBN 1-85898-619-2, 704 pp., £150

The Nordic Nations in the New Western Security Regime by Ingemar Dorfer, Baltimore: Johns Hopkins University Press, 1997, ISBN 0-943875-83-8 (hbk), £27, ISBN 0-943875-82-X (pbk), £13     

From rivals to partners: AirSea Battle and the US air force–navy relationship

AirSea Battle (ASB) has generated significant publicity, controversy, and debate among scholars, analysts, commentators, and observers of US defense strategy. However, a research gap exists concerning formal analysis of the impact of the operational concept on the relationship between the US Air Force (USAF) and the US Navy (USN). The impact of the ASB operational concept on the USAF–USN relationship is examined across the issue areas of strategy, budgets, weapons procurement, and training. These four issue areas represent important areas of historical conflict and competition between the Air Force and Navy. The conclusion is that ASB is ushering in a new era of Air Force–Navy partnership that advances the inter-service dynamic from “jointness” toward integration. The emergent USAF–USN partnership therefore represents a significant development in US defense politics and defense strategy.     

The elephant in the room

When United States (US) President Barack Obama announced in 2013 that he would host the first United States-Africa leaders' summit the next year, he was greeted with considerable scepticism. Many critics thought he was just playing catch-up with other countries and organisations which had been holding Africa summits for years, especially China. But, whatever the motives, the event itself proved to be a substantial success, probably re-setting US relations with Africa for many years to come.     

RAIN,GROWTH, AND CIVIL WAR: THE IMPORTANCE OF LOCATION

We re‐examine the Miguel et al. (2004 Miguel, E., Satyanath, S. and Sergenti, E. 2004. Economic shocks and civil conflict: an instrumental variables approach. Journal of Political Economy, 112(4): 725–753. [Crossref], [Web of Science ®] , [Google Scholar]) study of the impact of growth on civil war, using growth in rainfall as an instrument. Miguel et al. (2004 Miguel, E., Satyanath, S. and Sergenti, E. 2004. Economic shocks and civil conflict: an instrumental variables approach. Journal of Political Economy, 112(4): 725–753. [Crossref], [Web of Science ®] , [Google Scholar]) – in our view, erroneously – include countries participating in civil wars in other states. Restricting the conflict data to states with conflict on their own territory reduces the estimated impact of economic growth on civil war. We show how spatial correlations in rainfall growth and participation in civil conflicts induce a stronger apparent relationship in the mis‐classified data.