New cross-country evidence for 1965 to 1995 is presented on the link that runs from population change to economic growth. The estimates indicate that demographic change is a powerful determinant of income growth, operating mainly via the effect of changes in age structure. The estimates also indicate that the benefits of demographic change can be greatly magnified by a favourable policy environ...

A mathematical programming model is proposed for optimal cropping patterns under water de®cits in dry regions. Crops may be deliberately under-irrigated in order to increase the total irrigated area and possibly the pro®t. An operating policy will identify both the total area and the irrigation level allocated to a given selected crop taking into account the possible successors and predecessors...

In the literature on replacement/maintenance policies for systems of stochastically failing machines, it is generally assumed that the failure time parameters are known and the objective is to find a replacement policy that minimizes expected cost per unit of time. In practice, however, the variability of costs can be an important consideration. In addition, most managers would want to adapt to...

Three indicators are used to study the performance of a single purpose irrigation reservoir in Karnataka, India. The three indicators are reliability, resiliency and a productivity index. The performance of the reservoir is evaluated when it is operated with optimal operating policies over a sufficiently long period of time. Three different optimal operating policies are derived, having increas...

This paper presents an economic production quantity (EPQ) model with a periodic order quantity (POQ) policy, product reliability and periodic demand. The machine reliability has decreased over time; therefore, the rates of perfect and defective products reduce and increase over time, respectively. A fixed percentage of these products are reworked while the rest is wasted. Some equipment in thei...