A new economic computer model called Aspen is being hailed by economists as “the best thing that’s come along in a long time” for predicting and analyzing macroeconomic data. The program, developed at Sandia National Laboratories, creates a make-believe world comprising up to 10,000 households plus 1,500 factories. By manipulating certain factors, economists can watch the behavior of the agents and use that data for economic forecasting. Aspen’s results have turned up some surprises — during an economic slump, “the firms learned to cooperate,” says a Sandia economist. “We didn’t put that into the software. But when things stayed sour, the firms got together and helped each other out.” The size of Aspen’s world is vital: “With thousands of players, you see behavior you wouldn’t get in macro models,” says the software’s creator, who dreams of models with 100,000 agents or more. The software is useful for analyzing the causes of business cycles, both nationally and in specific industries. (Business Week 17 Mar 97)