ABSTRACT
Modern societies have developed a growing thirst for forecasting. Both the apocalyptic expectations of a millennium and the more prosaic, traditions of greeting centuries inevitably cast the eye forward to speculate about what is to come. Revolts and revolutions always catch the experts by surprise—witness Iran in 1978–1979. The tone of the predictions will be interesting as greet the 21st century. Many forecasts about technology, for example, bear a decidedly optimistic tone. The United States continues to provide a receptive audience for calculations that an additional dose of technology will be good for what ails. Distinguishing between extrapolation from trends and prediction of directional change, the third task in disentangling forecasts, involves a less familiar but intriguing analytical task. The simple fact is that there are only two basic ways to go in forecasting. The Big Cause approach to forecasting has an interesting, and clearly checkered, history.
