Understanding the McNamara Fallacy: The Tendency to Overlook Present Evidence

The McNamara Fallacy, also known as the Omission Bias or the See-Saw Fallacy, is a cognitive bias that refers to the tendency for people to overestimate the importance of information that is missing, and underestimate the importance of information that is present. This can lead to poor decision-making and incorrect assumptions about the likelihood of events.

The term "McNamara" comes from Robert McNamara, who served as the U.S. Secretary of Defense during the Vietnam War. He was criticized for his tendency to focus on the things that were not happening (i.e., the absence of evidence) rather than the things that were happening (i.e., the presence of evidence). This criticism is now known as the McNamara Fallacy.