
We adjust for population with murder rates. Why not for mass shootings? - necessity
http://www.latimes.com/opinion/op-ed/la-oe-lott-mass-shootings-adjust-for-population-20160731-snap-story.html
======
dalke
The editorial author writes:

> Using the traditional FBI definition, the EU and the U.S. each experienced
> 25 mass shootings during the first seven years of Obama’s presidency
> (January 2009 to December 2015).

where

> the FBI defines a mass public shooting as four or more deaths in a public
> place that are not part of some other crime, such as a robbery

Mother Jones has a list of US mass shootings from 1982-2016 at
[http://www.motherjones.com/politics/2012/12/mass-
shootings-m...](http://www.motherjones.com/politics/2012/12/mass-shootings-
mother-jones-full-data) .

I count 27 mass shootings in that time period.

> But other advanced countries such as France, Switzerland, Finland, Belgium
> and the Czech Republic also came in above the U.S.

That's falls into the "lies, damned lies, and statistics" category. It is not
statistically valid to make these comparisons.

[http://www.charlespetzold.com/blog/2015/07/De-Obfuscating-
th...](http://www.charlespetzold.com/blog/2015/07/De-Obfuscating-the-
Statistics-of-Mass-Shootings.html) works through the problem using a better
statistical model, and comes to the conclusion that the US rate per capita is
about 4x that of the OECD average. I will quote the conclusion from that
piece:

> To get meaningful information from data concerning mass shootings, it is
> necessary to be aware of statistical fluctuations that result from an
> insufficient numbers of incidents. Once that is done, it becomes obvious
> that the rate of mass shootings in the United States is significantly higher
> than the other OECD countries.

> Of course, this isn't an academic exercise. Nobody will be surprised to
> learn that there is political motivation behind these attempts to
> demonstrate that the United States doesn't have horrendous incidences of
> mass shootings and other gun crimes. If the United States has levels of gun
> violence comparable with the rest of the world, there is certainly no need
> for gun-safety legislation.

> Our political arena is open enough to debate these issues. But the debate
> should not involve the abuse of statistics. If people are opposed to gun-
> safety legislation, they should own the consequences of that opposition
> rather than try to hide those consequences behind a bogus interpretation of
> statistics.

> Actual lives are at stake.

~~~
jrnichols
> I count 27 mass shootings in that time period.

Mother Jones uses a different standard for what they consider a "mass
shooting." The FBI "defines a "public mass shooting" as one in which four or
more people selected indiscriminately, not including the perpetrator, are
killed"

Looking at the raw spreadsheet, Mother Jones (which has been notoriously anti-
gun) seems to be using 3 or more as their criteria for a "mass shooting." That
might account for the difference.

~~~
dalke
I didn't count the 5 entries in that period with 3 deaths.

They use the new (since 2014) definition of 3 deaths. Here's the relevant law:
[https://www.law.cornell.edu/uscode/text/28/540B](https://www.law.cornell.edu/uscode/text/28/540B)
.

You are correct - the Mother Jones table does include the killer, if the
killer also died. I checked the killings with 4 deaths. The suspected coffee
shop police killer was killed by police at another time, and the Alturas
tribal shooting killer was arrested. The killings with 5 and 6 deaths were all
done by a single person.

So that doesn't explain the discrepancy.

The editorial author believes the new definition was done for political
reasons, and prefers to use the older one. See
[http://nypost.com/2014/10/12/the-fbis-bogus-report-on-
mass-s...](http://nypost.com/2014/10/12/the-fbis-bogus-report-on-mass-
shootings/) for another op-ed by the same author.

You'll note that the author has "data on [US] mass public shootings from 1977
to 1999." Why, I wonder, did the author only report on a 7 year baseline,
rather than 40 years? That longer baseline would help with the regression to
the mean problem intrinsic to this analysis. He's had years to do that.

His NY Post piece even chides the FBI for using a too-short baseline since the
early 2000s had a fewer than average number of killing.

Going back to your "notoriously anti-gun" description. Why does it matter?
Mother Jones gave all of their data, with links to the primary source for
verification. My cursory spot check found no discrepancies.

Since the editorial author appears to be "notoriously" pro-gun, given his book
and op-ed pieces, but doesn't give the full data or explain the choice of
baseline - and does a poor job of interpreting the numbers - shouldn't those
conclusions be even more suspect?

~~~
jrnichols
> Here's the relevant law

Not sure if they're using that for "mass shootings" as it refers to what they
will consider a "serial killing."

I did find this interesting article about the varying definitions, though.

[https://www.washingtonpost.com/news/wonk/wp/2016/02/26/we-
ha...](https://www.washingtonpost.com/news/wonk/wp/2016/02/26/we-have-three-
different-definitions-of-mass-shooting-and-we-probably-need-more/)

> Going back to your "notoriously anti-gun" description. Why does it matter?

It matters to me because when I see them as a source, I know to do a little
more legwork and check the sources before sharing the information that they
have presented. Mother Jones is one of an unfortunately long list of websites
that I don't trust very much. The bright side to that is that it's spurred me
to dig further into topics.

~~~
dalke
Hmmm, you're right. I didn't find the correct US law.

A-ha! Found it! The bill which changed it was the Investigative Assistance for
Violent Crimes Act of 2012, 28 USC 530C(b)(1)(M)(i),
[https://www.gpo.gov/fdsys/pkg/PLAW-112publ265/pdf/PLAW-112pu...](https://www.gpo.gov/fdsys/pkg/PLAW-112publ265/pdf/PLAW-112publ265.pdf)
and the law text is at
[https://www.law.cornell.edu/uscode/text/28/530C](https://www.law.cornell.edu/uscode/text/28/530C)
:

> For purposes of this subparagraph — (I) the term “mass killings” means 3 or
> more killings in a single incident; and (II) the term “place of public use”
> has the meaning given that term under section 2332f(e)(6) of title 18,
> United States Code.

It looks like Mother Jones is using the current federal definition.

Agreed, just because there is a definition doesn't mean it's a good
definition. The idea that 18 people can be shot but only one killed should
still make it be a mass shooting, but the FBI wouldn't count it. That's the
argument given
[https://www.massshootingtracker.org/about](https://www.massshootingtracker.org/about)
, which uses a different definition to conclude there have been "1306 mass
shootings since 1/1/2013"

Does feedback like this help you adjust your confidence levels? That is, might
you think better of a Mother Jones analysis in the future, or give you less
reason do the legwork?

While on the other hand, this op-ed piece appears to have undercounted the
numbers, and for unspecified reasons uses "the traditional FBI definition"
rather than the current FBI definition. (I, and perhaps you also, thought he
was using that phrase to mean something like 'the current and long-held
definition', not 'the older definition, which I prefer').

Does that make you less likely to trust the general argument?

~~~
Turing_Machine
"Agreed, just because there is a definition doesn't mean it's a good
definition."

Whether it is a good definition or not is important, but you're not focusing
on the salient fact: the definition was changed, recently, which makes it
difficult to compare current data with older data.

"for unspecified reasons uses "the traditional FBI definition" rather than the
current FBI definition."

Perhaps because he wants to actually compare the rates over time without
talking nonsense.

At some level the cutoff for what constitutes a "mass shooting" is fuzzy. That
doesn't make it okay to do a straight comparison of data that uses one
definition with data that uses another definition.

~~~
dalke
It doesn't matter that the federal definition changed a couple of years ago.

The salient question is, given the data - no matter what definition is used -
does the analysis make sense?

I gave a link to a page which goes into that more carefully, and concludes
that a simple average, as the editorial author did, does not make sense.

This question about the definition is a side-issue. The fact that I cannot
reproduce the numbers does make me wary, but even if it were correct, the
conclusion drawn from that data is simply false.

One way to improve the confidence of the data, without more sophisticated
statistical analysis, is to increase the baseline. He already has a much
longer baseline for US data, and he elsewhere complained about the arbitrary
time definition for an FBI report which he said artificially skews the
results.

Why then did he choose the first 7 years of Obama, and not 20-30 years?

~~~
Turing_Machine
I can't believe you're seriously arguing that the definition doesn't matter.

Okay, let's define "mass shooting" to include people who are shot wholesale by
government action (by the way: why shouldn't it?), and increase the time frame
to _75_ years.

Now compare the U.S. to Europe, and your conclusions about the relative rates
will be...somewhat different.

The Netherlands lost about 2% of its population in WWII, the equivalent of
about 7 million deaths in a population the size of the current United States.

~~~
dalke
You don't need to believe it because that's not what I said.

I said "just because there is a definition doesn't mean it's a good
definition". That doesn't mean I think it's a good definition or a bad
definition. I personally prefer the definition used by
massshootingtracker.org, which concludes there have been 1300+ mass shootings
since 2013. However, I also think someone will argue about any reasonable
definition.

I also said "It doesn't matter that the federal definition changed a couple of
years ago." That doesn't mean I think any definition will work, only that for
the purposes of this analysis, we can choose either the old definition or the
new one - or any reasonable definition.

I'm willing to accept the old definition and focus on the _real_ "salient", to
use your term, issue, which is that the results of this op. ed piece are
worthless, because of poor use of statistics.

~~~
Turing_Machine
Why wouldn't a "reasonable definition" include people who were shot in large
numbers by murderous governments?

Take your time.

~~~
dalke
Because it doesn't fit the goal of the op. ed piece, which is what we are
talking about.

If anything, it says that mandated arming of large numbers of citizens
(conscription), and mandatory use of such weapons, leads to a higher number of
mass killings.

That's a different conversation than the mandated disarming of large numbers
of citizens.

~~~
Turing_Machine
"Because it doesn't fit the goal of the op. ed piece"

Translation: it wouldn't fit the political agenda of the op. ed piece.

~~~
dalke
I'm glad that you agree with me that your definition is not relevant to the
op.ed piece or to this entire thread.

~~~
Turing_Machine
That is quite clearly untrue, and you are no longer debating in an honest
manner (if you ever were).

Buh-bye.

~~~
dalke
If only more kibitzers were so polite.

------
SudoNhim
Grrr. If you adjust for population of course the top places in the list will
be dominated by small populations who've had a particularly bad time recently.

------
noisewaterphd
Let's just ban anything that can hurt anyone. Legislation will solve
everything.

I'm not "pro-gun", I'm pro-freedom, or pro-rights. Rights and freedoms come
with sacrifices. Giving up your rights for a false sense of security is naive.

Setting aside the infringement of rights topic for a moment, focusing on the
tool of destruction is never going to work. There is a much deeper, and more
complex problem at work here. We need to identify and understand it.
Simplified talking points for political purposes make me sick. As a nation we
are smarter than this, so why does it perpetuate?

Statistics don't matter, for either side, "gun-control" isn't going to solve
the problem. It isn't even _part_ of the solution.

Think about how ridiculous it sounds to ban all cars and pressure cookers...

"Shall not be infringed..." can not be taken lightly.

