Choices at various levels of uncertainty: An experimental test of the restated diversification theorem

Our “Restated diversification theorem” (Skogh and Wu, 2005) says that risk-averse agents may pool risks efficiently without assignment of subjective probabilities to outcomes, also at genuine uncertainty. It suffices that the agents presume that they face equal risks. Here, the theorem is tested in an experiment where the probability of loss, and the information about this probability, varies. The result supports our theorem. Moreover, it tentatively supports an evolutionary theory of the insurance industry—starting with mutual pooling at uncertainty, turning into insurance priced ex ante when actuarial information is available.     

Older people, work and equal opportunity

People in industrialized countries are living longer, having fewer children and retiring sooner. The proportion of older people in the population is rising; their labour force participation is declining. These trends are arousing apprehensions about future labour supply and pension financing as contributor/beneficiary ratios decrease. A widely advocated policy response is to seek higher participation rates, especially by raising pensionable ages and restricting early retirement. Little has been done to improve the labour market position of seniors. Three-pronged action is needed: promoting training, placement and workplace flexibility; changing attitudes through education and information; and prohibiting age discrimination in employment.     

Minimization of model inadequacy when observations subject to shift in means and variances

In this article optimality of experimental design for fitting a lower-order polynomial to a higher order response function for the situation in which observations may be subject to shift in means as well as in variances is considered. It is found that Karson, Manson and Hader‘s (1969) optimum designs provide pro-tection, in some sense, against model inadequacies even when observations are subject to shift in means and variances.     

Bayesian prediction for progressively censored data from the Burr model

Received: August 14, 2000; revised version: April 23, 2001     

End of an orthodoxy? The critique of sociology's view of Marx on class *

In this paper I comment critically on the dominant form of appropriation of Marx's theory of class and the state within what one might call the‘conventional’sociology of class in the post-war period. I argue that the typical mode of interpretation and assimilation has been highly selective and has taken a form that has rendered the proposed theory particularly vulnerable to sociological criticism especially in the light of changes in the structure of capitalist social formations in the twentieth century, although there is no suggestion here that the selectivity has been intentional. I contrast the dominant sociological construction and critique of Marx's theory of classes and the state with an interpretation drawn from recent scholarship, arguing that it is possible to document the contention that most theorems hitherto regarded both as central to Marx's analysis and as particularly susceptible to criticism were actually revised by Marx himself in his maturity as part of a more general process of intellectual formation and theoretical development. Many of these revisions have been widely discussed in debates within the world of Marx scholarship and some have undoubtedly been noticed in sociological interpretations of Marx. However, they have not led to the major overall reinterpretation of Marx's theory of class that is now long overdue.     

Crime and the city: Domestic burglary and the built environment in Tehran

Environmental criminologists have correlated crime patterns with the environmental and physical layout of places where crimes occur. This paper reports on some of the findings derived from a major research carried out in Tehran, focusing on the link between built environment and residential burglary. After a brief review of crime prevention approaches in the built environment and their theoretical basis, the paper examines how burglars select their targets, and investigates the significance of geographical distance and target hardening for crime prevention. It shows the limitations of distance and target hardening as deterrents, their potential impact on deepening the city's socio-spatial divide, and their negative implications for the quality of the urban environment.     

People as partners: Facilitating people's participation in public–private partnerships for solid waste management

Cities in developing countries are facing a double dilemma. On one hand, the urban population is growing rapidly, causing a huge increase in demand for waste management services. On the other hand, the traditional public sector is failing to respond to the increased demand for service. The public sector is constrained by resource and institutional limitations. It is often proposed that the solution lies in private sector participation. It is expected that the private sector, with its dynamism and flexibility, may fill in the service delivery gaps by forming partnership with the public sector. However, a third tier—the people—is often overlooked in the service delivery framework. Citizens can contribute significantly to service delivery. They can support the private sector with payment of service charges. But more importantly, they can play an active role in improving accountability and service quality of both public and private sector. This radical shift in people's role, from passive service receivers to active service partners, however, may not occur endogenously. External help from facilitating agencies may enable the public and private sector to form partnership with people for better service delivery. This article examines the role of facilitating agencies in developing tripartite partnership for solid waste management service in Bangladesh. The key lessons learned are: a number of obstacles prevented spontaneous partnership among the public sector, private sector and people; facilitating agencies were able to overcome the obstacles to form partnership of the three; and, the tripartite arrangement resulted in higher accountability and better service delivery.     

The Assessment of Probability Distributions from Expert Opinions with an Application to Seismic Fragility Curves

A method is developed for estimating a probability distribution using estimates of its percentiles provided by experts. The analyst's judgment concerning the credibility of these expert opinions is quantified in the likelihood function of Bayes'Theorem. The model considers explicitly the random variability of each expert estimate, the dependencies among the estimates of each expert, the dependencies among experts, and potential systematic biases. The relation between the results of the formal methods of this paper and methods used in practice is explored. A series of sensitivity studies provides insights into the significance of the parameters of the model. The methodology is applied to the problem of estimation of seismic fragility curves (i.e., the conditional probability of equipment failure given a seismically induced stress).     

On Order Statistics from Sine Distribution

We derive closed form expressions for the first two moments of order statistics from the sine distribution. For the higher moments, a recurrence relation is given. We also give a recurrence relation for the product moments. These relations will be useful for moment computations based on ordered data.