Chartering strategies for shipping companies

This paper describes a model which may be used in the evaluation of the relative effectiveness of policies used in the areas of ship chartering and the switching of combined carriers between the dry cargo market and the tanker market. The policies for chartering and market switching are expressed in the form of ‘desired proportions’ of the fleet operating in a particular charter-mode or a particular market. Graphical illustration of this form of expression of policies can be easily understood, so that alternative policies can be designed with relative ease. The effectiveness of a particular form of policy under various freight market conditions can be determined from the model, the use of which is illustrated by its application to the deployment of the fleet of an hypothetical shipping company. It is assumed that the feedback connection between the company's actions and the marketplace is negligible.     

Fertility decline and gender bias in

Although it is widely acknowledged that the preference for sons is a barrier to a decline in fertility, considerable disagreement exists as to what actually happens to this preference when fertility declines in a region of low female autonomy. By analyzing the data from the National Family Health Survey (NFHS), we present evidence from northern India to show that the preference for sons is reduced when the ideal family size becomes small, even though it does not completely disappear. This finding appears to contradict trends in the juvenile sex ratio and the incidence of female feticide that suggest the intensification of gender bias. We argue that the anomaly is the result of a diffusion of prenatal sex-diagnostic techniques in regions where there is a large unmet demand for such methods. Using the NFHS data, we estimate that in northern India, girls currently constitute about 60% of the unwanted births and that the elimination of unwanted fertility has the potential to raise the sex ratio at birth to 130 boys per 100 girls.     

Exchange curves for fixing batch quantities

The problem considered is that of choosing batch quantities to minimize costs, subject to the constraints that neither overall set-up costs nor overall set-up time can be increased beyond certain limits. Theoretical and graphical solutions are obtained for two possible formulations of the problem, and a simple practical procedure is suggested.