“Been There, Done That”: Perils, Pitfalls, and Promises of Long-Term Projections

Twenty-five years ago, a team led by Nobel laureate Wassily Leontief applied the United Nations World Input-Output Model to make forecasts of world fuel and mineral resources for the year 2000 and beyond. Ira Sohn, a member of that team, reflects on his experience with this long-term forecasting endeavor. Noting that long-term forecasting is fraught with uncertainties, Ira analyzes the sources of the forecasting errors made and suggests ways to improve long-term modeling. Copyright International Institute of Forecasters, 2008