What is a historical example of survivorship bias?
During World War II, early studies of damage inflicted on US bombers focused on the damage sustained by planes that made it back to their bases. The decision was made to reinforce the areas most often damaged by enemy fire.
It was soon realized, however, that this was excluding the most important sources of data—the planes that never made it back to base. It became apparent that the most important places to reinforce the craft were where they had not been hit. Because the planes that were hit there hadn’t returned.
This is an excellent example of survivorship bias, because the planes were literally the survivors, but they lacked the most important data.