Percentage Errors Can Ruin Your Day (and Rolling the Dice Shows How)

Foresight has printed many articles about the calculation, interpretation, and especially the dangers of percentage error metrics, such as the MAPE. Stephan and Roland now add to the list of dangers, showing how you can be led astray if you use the MAPE to select a best forecasting method or to reward forecast accuracy. Minimizing the MAPE is often not a good idea. Copyright International Institute of Forecasters, 201