ABSTRACT
A favorite pastime among some groups of quantitative scientists - demographers, ecologists, and economists in particular - is to propose "scenarios" for future events, based on the selection of a stipulated set of conditions. Scenarios are descriptions of predicted consequences of actions or inactions taken or not taken within a specific system. This predictive exercise, in the right hands, can offer useful insights and is widely employed in population studies. It is of course subject to many limitations, including new ones outlined in recent discourse on "chaos" theory, in which minute variations can lead to major shifts in the outcome of any predicted interaction.
