Living in nation with low gun ownership rate increases risk of being murdered (proof included)

[lawodevolution]

I used two sources:
2007 small arms survey: http://en.wikipedia.org/wiki/List_of_countries_by_gun_ownership
Murder rate by nation: http://en.wikipedia.org/wiki/List_of_countries_by_homicide_rate

I combined the data from each and came up with 31 nations in which I had both gun possession rate and murder rate data. The result is that the 15 nations with the lowest gun possession rate had an average murder rate of 10.3 and the 15 nations with the highest gun possession rate had an average murder rate of 2.2. I have the data listed near the bottom of the post.



Next I did a t value test.
A.
Mean1 = 2.2 murder/100,000 = M1
N = 15
(Value-mean)^2 / 14

USA, 5.4
(5.4-2.2)^2 / 14 = 0.7314
Yemen 3.98
(3.98-2.2)^2/14 = 0.2263
Switzerland 1.01
(1.01-2.2)^2/14 = 0.1029
Serbia 1.46
(1.46-2.2)^2/14 = 0.03911
France 1.60
(1.60-2.2)^2/14 = 0.02571
Finland 2.17
(2.17-2.2)^2/14 = 6.4285 * 10^-5
Greece 0.98
(.98-2.2)^2/14 = 0.106314
Canada 1.83
(1.83-2.2)^2/14 = 0.009778
Sweden 0.92
(.92-2.2)^2/14 = 0.1170
Austria 0.73
(.73-2.2)^2/14 = 0.1543
Germany .86
(.86-2.2)^2/14 = 0.128257
New Z 2.00
(2 -2.2)^2/14 = 0.002857
Saudi Arabia .92
(.92-2.2)^2/14 = .1170
Thailand 7.92
(7.92-2.2)^2/14 = 2.337
Australia 1.2
(1.2-2.2)^2/14 = 0.071428

X_1 = 2.2
S^2_1 = 4.169418
N1 = 15


B.
Mean2 = 10.3 murder/100,000 = M2
N=15

South Africa 37
(37-10.3)^2 / 14 = 50.92
Turkey 6.94
(6.94-10.3)^2/14 = 0.8064
Argentina 5.27
(5.27-10.3)^2 / 14 = 1.807
Italy 1.06
(1.06-10.3)^2/14 = 6.0984
Pakistan 6.86
(6.86-10.3)^2/14 = 0.8453
Spain 1.2
(1.2-10.3)^2/14 = 5.915
Russia 14.9
(14.9-10.3)^2/14 = 1.5114
Ukraine 7.04
(7.04-10.3)^2/14 = 0.7591
Brazil 25.2
(25.2-10.3)^2/14 = 15.858
Colombia 35
(35-10.3)^2/14 = 43.577
UK 1.49
(1.49-10.3)^2/14 = 5.554
Iran 2.93
(2.93-10.3)^2/14 = 3.87977
Philippines 3.82
(3.82 -10.3)^2/14 = 2.999
India 2.82
(2.82-10.3)^2/14 = 3.9964
China 2.36
(2.36-10.3)^2/14 = 4.503

S^2_2 = 149.03
X_2 = 10.3
N2 = 15

Results:

8.1 / sqrt ( 0.277 + 9.935)
8.1 / sqrt ( 10.21)
8.1/3.19567
T = 2.5346
For P=0.05
N total = 30

We compare to 2.04 that is on the P<0.05 (95% confidence interval) table, we are looking for our T value to be higher than this value (which it is).
This means we reject the null hypothesis and statistically these two means are significantly different.

Feel free to check my math.


The reason I used that statistical method above is because we use the same method to determine if a medication is good for a particular illness. I held this data to the same standard of statistical evidence that the health care system uses to rationalize using a medication.

Null hypothesis was that level of gun ownership does not effect rate of murder
Hypothesis A is that more guns = greater chance of having a lower rate of violence based on the data.

Hypothesis A IS supported by the data, and was being checked against the null hypothesis.
The null hypothesis is rejected

The conclusion is that higher rates of gun possession result in a lower risk for murder per 100,000 in a given nation.
This does not prove that increasing the amount of guns in a particular nation will decrease crime, it means that if you are going to move to another country, if the country you are moving to has a low rate of gun ownership, you have a higher chance of being the victim of murder than if you moved to a country with a high rate of gun ownership.


Data for gun ownership rates vs murder rates given by the links at the top.
Here are the 15 nations with high civilian gun ownership rates:
USA 90 guns per 100 people, 5.4 murders per 100,000 people
Yemen 61, 3.98
Switzerland 46, 1.01
Serbia 37.5, 1.46
France 32.0, 1.60
Finland 32.0, 2.17
Greece 31.8, 0.98
Canada 31.5, 1.83
Sweden 31.5, 0.92
Austria 31, 0.73
Germany 30, 0.86
New Zealand 26.8, 2.00
Saudi Arabia 26.3, 0.92
thailand 16.0, 7.92
Australia 15.5, 1.2

Mexico was the median, 15, 14

Now for the list of low possession rates
South Africa 13.1, 37
Turkey 13.0, 6.94
Argentina 12.6, 5.27
Italy 12.1, 1.06
Pakistan 12.0, 6.86
Spain 11.0, 1.2
Russia 9.0, 14.9
Ukraine 9.0, 7.04
Brazil 8.8, 25.2
Colombia 7.2, 35
UK 5.6, 1.49
Iran 5.3, 2.93
Philippines 4.7, 3.82
India 4.0, 2.82
China 3.5, 2.36

Nigeria 1.0, N/A (had to be excluded due to lack of murder rate data)