Tag Archives: probability

Always Go Beyond Numbers

People don´t understand probabilities.

“When people hear these analyses, however, they are not reassured but become more fearful than ever — they hadn’t realized there are so, many ways for something to go wrong! They mentally tabulate the number of disaster scenarios, rather than mentally aggregating the probabilities of the disaster scenarios.
Steven Pinker, Blank Slate
 
I think generally people don´t understand numbers, period.
 
Good example is the probability of someone becoming a NBA player. The odds are naturally low, but there is a good indicator that increases the probability. That indicator is height.

For a man between 6 feet to 6”2”, the chance of being in NBA is five in a million.
At 6”2” to 6”4”, the chances improve slightly to 20 to million.
Man between 6”10” and 7 it is 32000 in a million (3.2%).
And for men over 7 seven feet tall, 17% of them are in the NBA right now*. So every six guy over 7ft you would encounter would be NBA player. Because massive growth is quite often attributed to some disease, it is even more likely that healthy seven-footer is a NBA player. So with narrowing the group, we have actually find quite a good indicator of your probabilities of becoming NBA player.

It is always important to go beyond the numbers.

JJ Redick

JJ Redick is one of the rare NBA player with shorter wingspan than his height

Even the short NBA players are not really that short. Nate Robinson is only 5”7”, but his wingspan is 6”1”. NBA players in general have almost double more wingspan than regular people. Generally it is really rare that a player has shorter wingspan than his height. Yao Ming was one of them, but on the other hand he was 7”6”. So if you would need to predict someone´s ability to be a NBA player and you would need to rely only on two data points: height and wingspan would be probably the best with the former being more important.

*Stats read from a great book by David Epstein: The Sports Gene.

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Why You Should Not Fear Flying?

I was flying to Jakarta on New Year´s eve. About midway on the flight there was quite heavy turbulence quite close to the area of AirAsia crash. Nothing I would usually be worried about. When other passengers started praying and doing cross signs, I have to admit that I started to feel a little bit queasy as well.

Being afraid of turbulence after major accident is human, but it is not rational.

Although this year has been horrendous for airline industry (especially for Malaysian airlines), it is quite far from the most morbid years of aviation. Especially in relation to the skyrocketed in recent years, the flying still remains the safest way to travel. The most dangerous part of commercial flying is the drive to the airport.

After 9-11 over 1.4 million people changed their travel plans to avoid flying opting for driving. This caused over 1000 additional car accident fatalities. The most vivid fears are irrational, but easily explained:

1. We fear things we feared in Stone Age.
Although we should probably be more worried of our mobile phones in our front pockets, we tend to fear snakes, insects and spiders, which are quite minor threat nowadays. Being afraid of heights and flying made sense before the time of airplanes, not that much anymore.

2. We fear things we can´t control.
Everyone thinks that they are above average driver and the rest of the drivers are morons. We constantly overestimate our grip of the situation and underestimate the other people.

3. We fear things that are immediate.
Smoking kills you. It just does not kill you right away. Small odds add up and we fail to see them. One cupcake occasionally does not harm you. One cupcake a day might add few extra pounds. One cupcake after every meal might result in obesity and diabetes.

4. We fear things that are fresh in our memory.
After flight accident we are more prone to react to the turbulence. Because newspapers seldom write about people dying to diabetes, we overestimate that homicide is more lethal than it.

So there should be nothing to fear about…

Even though I know all of the above things on that particular flight, I was still a little bit worried. This is an important lesson about human behavior. We might know all the rational facts but still end up acting irrationally. Then we try to post-rationalize those irrational decisions.

Especially when asked afterwards in focus groups.

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