Survivorship bias is the logical error of concentrating on the people or things that "survived" some process and inadvertently overlooking those that didn't because of their lack of visibility. This can lead to false conclusions in several different ways.

During WWII, statistician Abraham Wald was asked to help the British decide where to add armor to their bombers. After analyzing the records, he recommended adding more armor to the places where there was no damage. This seems backward at first, but Wald realized his data came from bombers that survived. That is, the British were only able to analyze the bombers that returned to England; those that were shot down over enemy territory were not part of their sample. These bombers' wounds showed where they could afford to be hit. Said another way, the undamaged areas on the survivors showed where the lost planes must have been hit because the planes hit in those areas did not return from their missions.

Wald assumed that the bullets were fired randomly, that no one could accurately aim for a particular part of the bomber. Instead they aimed in the general direction of the plane and sometimes got lucky. So, for example, if Wald saw that more bombers in his sample had bullet holes in the middle of the wings, he did not conclude that Nazis liked to aim for the middle of wings. He assumed that there must have been about as many bombers with bullet holes in every other part of the plane but that those with holes elsewhere were not part of his sample because they had been shot down.

With that in mind, compare the number of mass shootings that happen in "gun free zones" such as schools and universities, and the number that happen at gun-rich zones, such as shooting ranges or gun shows. ... Exactly. I'm not suggesting that EVERYONE HAVE GUNS is the answer, I'm suggesting that if we as a society are going to make an honest effort to find a solution to this problem, let's not only take into account incidents such as the Newtown shooting, where everything went wrong; but also include incidents such as the San Antonio theater shooting, where (all things considered) everything went right. Only by taking all of the information into account -- not just the selective bits that reinforce our already preconceived notions -- will we be able to understand the true nature of the problem.

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Nice.

Will be interesting to see if the anti gun group are intelligent enough to understand this !

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Excellent post, thanks Emmerich.

Of course, mass shootings do not always happen in gun free zones.
There seems to be no corroborating evidence to suggest that shooters pick gun-free zones.
Most mass shooters choose targets because of underlying issues they have had with people at the location.

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Thanks for the cool bomber story.

I am trying to figure out how it might apply to the gun safety issue.

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Very good! Sometimes the obvious is not so obvious. It appears that your skepticism regarding the gun grabbers not being able to understand has been substantiated by two of them so far.

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I haven't seen any 'gun grabbers' post yet Larry...

If you refer to Tom and myself, it seems like we understand the concept well.

Maybe you could show evidence that correlates the selection of target for mass shootings and gun free zones?
Guess that bit wasn't in the email eh?
All evidence seems to suggest that the shooters chose their targets based upon who they wish to shoot/hurt/kill, not due to a lack of guns.

Furthermore, I do not recall Tom or I supporting gun free zones, speaking out in favor of them or in any way suggesting that they are good or bad.
My issue is the zealots who make erroneous claims that the reason there are repeated shootings at schools is due to the gun free zone.
That assertion is simply not true.

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On some nights I still believe that a car with the fuel gauge on empty can run about fifty more miles if you have the right music very loud on the radio. - HST

1983 300SD - 305000
1984 Toyota Landcruiser - 190000
1994 GMC Jimmy - 203000

https://media.giphy.com/media/X3nnss8PAj5aU/giphy.gif

I'm under the impression that most mass shootings take place in gun rich environments--war zones.

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exactly.look back all the shooters had a beef with the people or the place they shot up.

Excellent point.

I am no gun grabber.

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..I also have a 427 Cobra replica with an aluminum chassis.

Your original comparison is apt, but your comparison to gun shows/shooting ranges isn't, because those either aren't consistent or likely to have a lot of people, which the places that this sort of crime have in common. In this case, it's not weak points that someone is going after, but points that provide a lot of people and are usually open.

Someone who snaps and wants to kill a bunch of people probably isn't going to wait a few weeks for the nearest gun show, travel to get to one, or even figure out where one is. Similarly, shooting ranges don't tend to have a lot of people. Schools/theaters/malls are usually picked because they usually have a lot of people (more than shooting ranges) and they are well know/easy to get to.

Thats a bit like saying most electrocutions occur on the electric chair !!

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I no longer question authority, I annoy authority. More effect, less effort....

1967 230-6 auto parts car. rust bucket.
1980 300D now parts car 800k miles
1984 300D 500k miles
1987 250td 160k miles English import
2001 jeep turbo diesel 130k miles
1998 jeep tdi ~ followed me home. Needs a turbo.
1968 Ford F750 truck. 6-354 diesel conversion.
Other toys ~J.D.,Cat & GM ~ mainly earth moving

I gotta at least have one cup of coffee before I can take eggheads.

Facts only confuse and frustrate legislators. Show me the money.

Did you hear the one about the gun-grabber who shot up a gun show?

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