The most popular article on my Efficient Librarian website is Deal or No Deal Mr. Hall – How We Misunderstand Probability. That article was framed with a real story from the game show Deal or No Deal. This week I published a follow up article to dive deeper into the Deal or No Deal problem to demonstrate the fact that possibilities are not probabilities.

Below is the start of the article:

When are airplane comes in for a landing there are two possible outcomes: a safe landing or a crash landing. Therefore, what is the probability that the plane will crash?

Recently during a presentation of my seminar, Why Did I Make that Dumb Decision?  Understanding Common Fallacies of Decision Making and How to Avoid Them, I asked this question to the audience. Immediately, someone answered 50%. 

Of course this was not accurate. Commercial airplanes rarely crash. The website, FlyFright, shares government statistics that show odds of a plane crashing are 0.000001%. Also, there is a 1 in 816,545,929 chance of dying in a plane crash.

In fact, the most dangerous part of air travel is driving to and from the airport! Data from the Florida Highway Safety and Motor Vehicles department shows 3,454 fatal motor vehicle crashes in 2021. That is only one state out of 50! Given the higher frequency of car crashes, why are more people afraid of flying than driving? One reason is that we are primed to hear about plane crashes since these rare incidents are covered widely in the national media. Car crashes by contrast only get brief mention on the local news.

This example highlights the simple fact that possibilities are not probabilities. In the majority of cases where there are multiple possible outcomes, they are not equally likely to happen. Yet, our minds often default to thinking all possibilities are equally likely. This can lead to poor decision making.

Read the rest of the article on the Efficient Librarian website.