RADIOCARBON DATES FROM THE OXFORD AMS SYSTEM: ARCHAEOMETRY DATELIST 3

This third list of accelerator dates includes material dated in the same period as datelist 2 (Gillespi?et al. 1985) and subsequently. The dates have been achieved by the same methods as described there.     

Urban Neighborhoods as a National Resource: Irreversible Decisions and Their Equity Spillovers

The differential timing and pace of private versus public sector disinvestments in declining neighborhoods have some positive spillovers for their residents. Public services are not withdrawn or reduced as rapidly as private investments and the opportunity is preserved for future redevelopment or rehabilitation. This “public service bonus” is vulnerable, however, during periods of austerity and general retrenchment. During such crises, the pressures to rationalize service provision are able to overcome local political and bureaucratic resistance to service reallocations. The analysis is based upon the investment theory literature dealing with irreversible decisions and is exemplified by the reallocation of services in New York City's declining neighborhoods during the past decade.     

Activity Levels at Hub Facilities in Interacting Networks

Hubs are a special type of central facility which are designed to act as switching points for intemodal flows. For instance, a set of ten interacting cities might all be connected to one of two major hubs. All flows between the cities would then be routed via the hubs. There is an obvious saving in the number of routes necessary to interconnect the cities when hubs are utilized, with a concomitant high level of activity at the facilities. This paper takes a heuristic approach to the evaluation of networks and hub locations to find locally optimal designs. It is shown that minimization of transportation costs may require assignment of nodes to a facility other than the nearest. A discount on the interhub transportation costs promotes a wider spacing of facilities. In a system with several hubs, minimization of total hub usage tends to concentrate demand very heavily into one central facility.     

Rural-urban migration and urban employment opportunities in Nigeria

The author suggests that most studies of rural-urban migration in the third world today are based on the European experience during the Industrial Revolution. He contends that the assumption that most migrants find wage employment in a rapidly growing modern industrial sector is not valid, particularly in Western Africa, where the pace of industrialization lags behind the rate of urbanization. Data from Nigeria are used to show that many potential migrants are aware of this situation and migrate seeking self-employment in informal sector trading activities.     

UPPER BOUNDS ON THE SIZES OF INTERREGIONAL FEEDBACKS IN MULTIREGIONAL INPUT-OUTPUT MODELS*

ABSTRACT. Upper bounds are presented for a measure of the overall percentage error caused in a multiregional input-output model when interregional feedback effects are ignored. This error figure is thus a measure of the magnitude of interregional linkages. The upper bounds are expressed as a function of the levels of self-sufficiency in the regions in the model and of the norms of the regional technical coefficients matrices. Experimental results are presented for a variety of examples that are thought to reflect real-world situations, and it is clear that in many cases the upper bound (and hence the error) is extremely small. The implication is that single-region input-output models may be adequate for a variety of questions.     

Reconstructing and deconstructing Hume's political thought

David Miller, Philosophy and Ideology in Hume's Political Thought, Oxford, Oxford University Press, 1985, pp. 218. $15.50 (paper)

Frederick G. Whelan, Order and Artifice in Hume's Political Philosophy, Princeton, Princeton University Press, 1985, pp. 393. $US35.00 (cloth)