The fallacy of projections

In September 2006, the IMF in its Global Economic Output report projected that the US will be “the engine of global economic growth despite some uncertainty in the housing sector.” In its July 2008 report, less than two years later, the IMF revised downward (again) its projections for US economic growth to 1.3% (from 3.2% and 2.2% in the previous two semi-annual reports). The world’s most sophisticated economic forecaster failed to project the size and impact of one of the most serious financial crises in our modern history on the most monitored economy, although that event was on the radar screen for two years. Recently I spent a few hours with a colleague of mine trying to “fit” the actual financial results of a company we had invested in into the model we had built for that company prior to that investment. The bottom-line projections were close to the actual