Q6.8 Perhaps the most famous early econometric forecasting firm was Wharton Economic Forecasting Associates (WEFA), founded by Nobel Prize winner Lawrence Klein. A spin-off of the Wharton School of the University of Pennsylvania, where Klein taught, WEFA was merged with Data Resources, Inc., in 2001 to form Global Insight. Describe the data requirements that must be met if econometric analysis is to provide a useful forecasting tool.