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Artwork: Gold Confiscation Executive Order 2013
Qianhai is a toe
Using the ex post approach and an appropriate statistical model developed after analysis of errors in international forecasts, we estimated prediction intervals for the current U.N. forecast. These intervals are constructed on the assumption that errors in current projections resemble those in past projections made after 1970. Our results suggest that the uncertainty in country projections is quite variable and is dramatically greater than suggested by U.N. high-low scenarios, with a typical 95-percent range more than twice as wide as the U.N. high-low intervals.
Regional 95-percent intervals are similarly variable but generally much narrower than country intervals. For developing regions, however, they are still consistently wider than U.N. high-low intervals. Across regions, the median 95-percent interval in 50-year projections was 40 per-cent wider than the U.N.’s high-low interval. However, prediction intervals are proportionally narrower for industrial regions and for the world as a whole. In these cases, our estimated prediction intervals are narrower than the intervals defined by the U.N. high-low scenarios. The world prediction interval also suggests a greater possibility of a downside than an upside error, making sustained population decline appear quite unlikely during the next 50 years.
World population in 2050 : new revision but what about accuracy?