This paper begins with the observation that the constrained maximisation central to model estimation and hypothesis testing may be interpreted as a kind of profit maximisation. The output of estimation is a model that maximises some measure of model fit, subject to costs that may be interpreted...

The relative merits of different systems of property rights to allocate water amongdifferent extractive uses are evaluated for the case where variability of supply isimportant. Three systems of property rights are considered. In the first, variablesupply is dealt with through the use of water...