Monday, October 09, 2017

Gun Control and Homicide Rates

Some recent comment threads on Slate Star Codex, my favorite blog, have dealt with the always lively issue of gun control. One standard argument is "we know gun control laws work because the U.S., which has relatively few restrictions, has a much higher homicide rate than countries such as Canada or the U.K., which have much more restrictions."

One response sometimes offered is that there are other countries, such as Mexico and Brazil, with both restrictive laws and homicide rates much higher than in the U.S. That then gets into the question of what comparisons are more relevant, in what respects the U.K. is more like the U.S. than Brazil is.

An alternative approach, which I think more useful, is to ask whether the difference in homicide rates existed prior to the difference in regulation. The web makes that question much easier to answer than it would have been twenty years ago. 

In the case of the U.K., the answer is pretty clear. According to the Wiki page on Firearms Policy in the U.K., the first restrictive legislation was the pistol act of 1903, but it had little effect:
The Act was more or less ineffective, as anyone wishing to buy a pistol commercially merely had to purchase a licence on demand over the counter from a Post Office before doing so. In addition, it did not regulate private sales of such firearms.
The first  significant restriction was the Firearms Act of 1920. There were additional acts in 1937, 1968, 1988, 1997 and 2006.

The data on Homicide rates per 100,000:


Year U.S.  England&Wales Ratio
1900 1.2 0.96 1.3
1910 4.6 0.81 5.7
1920 6.8 0.83 8.2
1930 8.8 0.75 11.7
*1946 6.4 0.81 7.9
1950 4.6 0.79 5.8
1960 5.1 0.62 8.2
1970 7.9 0.69 11.4
1980 10.2 1.11 9.2
1990 9.4 1.09 8.6
2000 5.5 **1.71 3.2
2010 4.8 1.14 4.2


*No data for the U.K. 1940-1945
**The figure is for the U.K. rather than England and Wales

Looking at those data, it is hard to believe that the reason the U.K. has a lower homicide rate than the U.S. is restrictive legislation.

My point here is not that gun control doesn't (or does) work. I wouldn't be surprised if some restrictions on firearm ownership reduced the homicide rate, but if so, the effect on the U.S./U.K. ratio is lost in the noise. My point is rather that the sort of factoids that show up in this sort of argument, even when they are true, are rarely as solid evidence as those who offer them claim.

This would be a better post if I had a good example on the other side of the same debate. I don't, but perhaps someone reading this can offer one.


11 Comments:

At 3:44 PM, October 09, 2017, Blogger Lawrence Kesteloot said...

In the great book "Nine Crazy Ideas in Science" (http://amzn.to/2xsXZ9k), chapter 2 investigates gun/crime and concludes that gun laws (and gun ownership) have little effect on crime. (He's mostly debunking the idea that more guns means less crime.) David, I think you'd like the book, it seems like the kind of analysis you like to do here. Also, I met your son at Burning Man! Had a great time chatting with him in Kidsville.

 
At 5:02 PM, October 09, 2017, Blogger Carl M. said...

Interesting how England is just as violent as before gun control.

 
At 6:56 PM, October 11, 2017, Anonymous Anonymous said...

Off topic.
We went from "There are frickin' Nazis in Virginia!" to "Rocket Man is gonna nuke the US!" to "Republicans will not end Obamacare!" to "NFL players are disrespecting the flag!" to "Accountants are going Postal!" to "American Progressives get angry because Secession is not allowed outside the US!" to "A rapist pawn has just lost his protection and has been sacrificed for some obscure reason we will never know."
It is always react, react, react.
Tedious. What are they trying to hide?

 
At 7:18 PM, October 12, 2017, Blogger Thomas Mazanec said...

What happened in the US between 1900 and 1910? The murder rate nearly quadrupled, then stayed within a factor of two or so for a century.

 
At 10:46 PM, October 12, 2017, Blogger David Friedman said...

Thomas:

My guess is that it's a change in how the data was collected or defined, but I don't know.

 
At 10:28 AM, October 14, 2017, Blogger Geech said...

I once read a book called Guns and Violence: The English Experience that did a similar comparison and reached the same conclusion.

One of the random digressions in that book indicated that British police were historically unarmed not due to low crime rates but to assuage fears of a police state.

 
At 2:01 PM, October 14, 2017, Blogger montestruc said...

I am working on a paper on the subject, and have found the following.

First off crime data, what is recorded here are absolute numbers of incidents, not rates per population.

https://www.gov.uk/government/statistics/historical-crime-data

You need to download several spreadsheets of data from this site, look at the years covered, note that the numbers of crimes are reported, not the per 100,000 population data. You need to calculate that so you need population data that you can get here:

https://www.ons.gov.uk/peoplepopulationandcommunity/populationandmigration/populationestimates/adhocs/004358englandandwalespopulationestimates1838to2014

We only need from 1900 to 2000, or in the case of the crime of “violence against the person” (VAP), till 1998, as the British changed how that crime was recorded that year such that doing reasonable analysis of that became problematic. This being because they changed a significant number of definitions as to what was and was not VAP, making comparison across that time boundary problematic.

So my paper will not involve data from after 1998, I am looking at the effects of gun control laws in England & Wales over the 20th century. I am treating VAP data it as if the century ends in 1998.

Significant gun laws were enacted in 1920, 1937, 1968 and 1988.

I have calculated the rates of murder, rape, robbery, and “violence against the person” VAP per 100,000 population per year.

If you want I can email you the graphs.

 
At 12:42 AM, October 15, 2017, Blogger David Friedman said...

Montestruc:

Please do.

 
At 12:16 PM, October 16, 2017, Anonymous Anonymous said...

Just spit-balling, but with the big peaks in the 30's and 70's, wouldn't that work out fairly well with drug/alcohol prohibition? Alcohol in the 30's and drugs in the 70's?

 
At 11:14 PM, October 17, 2017, Anonymous RJ Miller said...

Something to always be ready to share when UK crime statistics are brought up:

http://rboatright.blogspot.co.uk/2013/03/comparing-england-or-uk-murder-rates.html

They don't record a murder as an actual murder until someone is convicted for the killing. I think by that standard our murder rate would appear to be only 60% or so of what it really is because that's our national clearance rate: https://www.usatoday.com/story/news/2016/12/30/chicago-murders-clearance-rate-2016/96009878/

Naturally some of the most violent cities have lower clearance rates, something worth looking into when it comes to crime reduction: https://www.ncjrs.gov/pdffiles1/jr000243b.pdf

Anyhow, that difference in definition that the UK has really throws a wrench into the idea that people can draw conclusions about gun laws strictly from reported murder rates alone.

 
At 3:24 PM, October 18, 2017, Blogger David Friedman said...

RJ Miller:

I have seen that claim but have not seen any support for it. I followed up the "a report to a select committee of Parliment." It's a memorandum by Colin Greenwood as an appendix to the minutes of evidence, not an official government statement of any sort. Colin Greenwood is a retired police officer critical of U.K. gun regulation.

Do you have any official statement by the U.K. government supporting the claim? I have not seen one so suspect it is a bogus factoid, of the sort that often shows up on controversial issues.

 

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