On the generalization of Rao,Hartley and Cochran's scheme

Summary The problem considered in this paper is a generalization of the usual Rao, Hartley and Cochran (RHC) scheme. In the usual RHC scheme the population ofN units is randomly divided inton groups wheren is the size of the sample. In this paper we propose to divide the population under consideration into (n+k) random groups wherek is some positive integer. Then a sample ofn groups is selected by using simple random sampling without replacement (SRSWOR). The expressions for the unbiased estimator of population total, its variance and the unbiased estimate of variance have been obtained under the proposed sheme. The condition under which the proposed sheme is more efficient than the usual RHC scheme has also been investigated.     

De Industrieele „Trusts” der Vereenigde Staten van noord-Amerika

November 19015 December     

Vulnerability and industrial hazards in industrializing countries: an integrative approach

The extra vulnerability of industrializing countries to environmental problems and industrial accidents cannot be understood or solved by a ‘normal’ scientific analysis. Aspects of the social and institutional context must be included, through analyses based on post-normal science. The standard two-dimensional classification of PNS is modified to have axes ‘social ‘and institutional vulnerabilities’ and ‘complexity of technological hazards’. The analysis is mainly applied to the case of the relatively rare accidents with catastrophic potential. In these, the deaths per accident in India, Mexico and Brazil are much greater than in the industrialized countries. This discrepancy arises partly from location of such plants near residential communities for marginalized workers and their families. Other socio-political factors are relevant, as the role of these countries in the global production system, the enforcement of safety and planning laws, quality of housing, and lifestyle of residents. Reducing the vulnerability of industrializing countries will therefore require major social policies and a comprehension of the limits of the normal scientific and economic approaches to such problems.     

Migration consequences of welfare reform

We investigate whether recent changes in welfare policy affect the migration of low-educated unmarried mothers. Estimates indicate that welfare reform is associated with an increase in employment-related intrastate migration, and a decrease in non-employment related migration, both within and between states. The net effect was a small increase in intrastate migration and a small decrease in interstate migration. The close link between migration and employment suggests that welfare reform has motivated low-income women to move for economic reasons. In general, welfare policy appears to have a much larger effect on residential location because of its relationship to employment than because of benefit differences between states.     

Quasi‐rational and ex ante price expectations in commodity supply models: an empirical analysis of the US broiler market

A statistically optimal inference about agents' ex ante price expectations within the US broiler market is derived using futures prices of related commodities along with a quasi‐rational forecasting regression equation. The modelling approach, which builds on a Hamilton‐type framework, includes endogenous production and allows expected cash price to be decomposed into anticipated and unanticipated components. We therefore infer the relative importance of various informational sources in expectation formation. Results show that, in addition to the quasi‐rational forecast, the true supply shock, future prices, and ex post commodity price forecast errors have, at times, been influential in broiler producers' price expectations. Copyright © 2003 John Wiley & Sons, Ltd.     

Additive and Multiplicative Uncertainty Revisited: What Explains the Contrasting Biases?

above the certainty level while for additive uncertainty the price should be lower than the certainty level. This note gives an intuitive explanation for the result after first presenting a parsimonious review of the two models. We also discuss which, if either, of the two models is more realistic. Received December 14, 2001; revised version received July 16, 2002 Published online: April 30, 2003 We thank referees for helpful comments. Ciaran Driver would like to acknowledge the research facilities from ANU, Canberra for their help in writing this paper.     

Tourism development in the SADC region: The opportunities and challenges

This article presents an assessment of recent tourism performance in the countries of the Southern African Development Community region, as well as an evaluation of future prospects. It examines growth rates and source markets in developing a profile of current tourism to the region. It identifies and assesses the current and probable future impact of a range of issues and problems, which are serving either to help or hinder tourism development. It suggests necessary actions for facilitating the accelerated development of tourism. The article also analyses the countries' tourism development policies and their competitive standing with other parts of Africa and other world regions from the market's viewpoint. It evaluates future growth prospects for the region by relating these various strands of analysis to the assessments made in the World Tourism Organization's Tourism 2020 vision study. The conclusion is one of qualified optimism: the natural and sociocultural resources of the region match the growing tastes of the international tourism market but, without concerted action to improve international access and tackle the major (real and imagined) threats to tourist safety prevailing in the region, growth rates will continue to be below their potential. The region's physical remoteness from the military theatre of action consequent to the 11 September 2001 terrorist attacks in the United States could well bring the countries of the SADC, and especially South Africa, some benefit from being perceived in tourist-generating markets as safe from these activities.