So I think it's fair I let you know my personal beliefs on Gun issues with the United States:
- At Present, I am not a gun owner. I have no need to own a gun. I have no interest in owning guns. I do not plan to buy a gun in my immediate future.
- I personally think that I should never be trusted with a fire arm, but I am not opposed to ownership if my circumstances change.
- I am in no position to tell my fellow citizens how they should or should not feel about guns. I ask my fellow citizens not to impose their feelings in the matter on me.
- Despite not owning fire arms at all, I do believe I should know what my rights are with respect to the Constitution and current laws.
- I am open to gun control measures if they are proven to work with the Constitution and control for an obvious gap in the law OR prevent an obvious scenario from that said gap.
- I believe in the right to self-defense with fire arms as a valid excuse for ownership. I believe the founders intended the citizens to be armed and ready to fight their new government if need be AS THEY HAD JUST FINISHED DOING. I do not believe the current United States Government is so far gone that this should occur in near future.
So, there are a few things that will tip those numbers, and there are a lot of studies that are thrown out that can confuse the issue. Some comparison statistics are not provided, some represent totally other things, and so on and so forth.
To Answer your question, I want to first point out some numbers you are using are wrong:
The homicide rate of the United States is 4.88 of 100.000 inhabitants. Compare this to the UK (0.92), Germany (0.85), Spain (0.66), or Japan (0.31).
These numbers are the total murders per capita for their countries. Criminal Homicide by Fire Arms are 3.60 (US), 0.06 (UK), 0.07 (Germany), 0.15 (Spain), and 0.0 (Japan). Taken at this look, the premise that more guns = more criminal Homicide does look more impressive, as the U.S. is still mostly gun crime are the predominant issue.
However, this does not prove the issue. We have to prove that these numbers are directly related to the number of guns in each country. These numbers are given as "per 100 residents" but can easily be converted to per capita (100,000) by multiplying the number by 1,000:
The United States has 101.5 guns per capita (aka More guns per capita than PEOPLE per Capita!). The comparison numbers are 6.6 (U.K.), 30.3 (Germany), 10.4 (Spain), 0.6 (Japan). These numbers include only both Legal Fire Arms and Illegal Fire Arms in civilian circulation. And then we take one more step.
To Prove more guns equals more Criminal Homicide, we will have to multiply the total gun numbers by 1000 (Making it Per Capita) and then divide the death by criminal homicide by the total gun numbers. Europe and Japan come out as follows:
UK: 9.09 x e-6
Germany: 2.31 x e-6
Spain: 1.44 X e-5
U.S: 3.54 e-5
(Source: List of Countries by Fire Arms Related Deaths)
So, yes, the United States has more fire arm homicides than the four countries you showed to us... but at a rate of homicide per gun, we're seeing some funny numbers. The U.K. and Germany are lower by a factor of 10... BUT... look who has the higher number of murders per gun: the U.K.... which has less gun related homicide than Germany (0.07 and 0.06) despite Germany having nearly five times the number of fire arms than the U.k. Similarly Spain has less than half of the murders per gun as the United States despite the United States literally having more fire arms than it does people (Ten times that of of Spain). Heck, at these numbers, if you want to round the U.K. to 1.00 X e-5 no one would really blink in any other stat.. The United States has a homicide per gun rate of 3 times that of the UK, despite having 15 times more guns.
I'm going to leave this part blank because I have to swap computers, but I'll put some of the reasons why the numbers come out so weird. The TL;DR: of that section will basically be there are cultural elements at play.
EDIT: Additional Discussion:
Okay, so long weekend aside, but there are other issues that may likely be drawn. If we look at the the total death rate by guns (including criminal homicide, suicide, accidental death, and unknown reasons) we find the rate of individual incident per capita vs. guns per capita the United States is only just slightly worse than Japan (1.04 x e-4 vs. 1.00 x e-4). This is because while Japan does have less guns than the United States available for civilian use, those that they do have are used for gun inflicted suicide at a rate that puts their total incident per gun level close to that of the United States. In fact, in the United States, Canada, and Europe, the general rule of thumb is that the rate of gun related suicide is much larger than gun related homicide, nearly universally. In fact, while there are a number of countries with higher total gun related incidents than the United States (10.6 per 100,000), the United States has the highest incident rate of nations where Suicides are a larger contributor than Homicides to total incidents. Brazil for example, has a total incident rate of about 21.2 per 100,000 of which the number of Gun Related Homicides dwarves any other contribution to incidents (19.99 per 100,000).
In these situations, there are contributing factors from a cultural stand point that contribute. Brazil is a majority Catholic and Christian country, and the Religion has strong taboos against Suicides (The Bible says a thing or two about killing, but apparently that's an issue of a different horse.). Mean while, Japan has a strong cultural taboo against causing other people trouble, which factors into their very very low murder rate in general (the family of criminals also pay for their jail time... if the family cannot pay, the criminal will do manual labor during his stay). They also do not have a cultural taboo on suicide (until recently).
Another undisclosed factor in the statistics, is that in the United States, about 88-93% of the total guns quoted are legally owned by the owner (meaning they bought and paid for the weapons through legal means). This statistic varies because the illegal owners are not known and tracked beyond guess work made by law enforcement. This leaves about 12,180 illegal fire arms per 100,000, and it's estimated that 80% of all gun related crimes are committed by these weapons (2.88 homicides out of 3.60 per 100,000). I won't compare these crime figures to the other nations because I do not have the data on legal vs. illegal fire arms in the other countries. It's important to note that you can drop the United States total homicide rate significantly if you dropped the four cities with the highest per capita homicide rates (St. Louis, Baltimore, Detroit, and New Orleans). The area of the United States between the coastal areas is not typically densely populate and these tend to be the areas of highest gun ownership.
Now the next question is that of these contries, I belive the United States is the only one that allows fire arms for self-defense purposes, and these numbers are hard to track. The incidents of self-defense use of guns is estimated to be between 65,000 - 2.5 million incidents per year (The vast majority will never involve pulling the trigger on the fire arm used in such a manor). The reason for this long gap is that the two studies used different criteria, with the lower levels being explicit incidents with guns pulled by the victim, while the larger number includes examples of the criminal being deterred from crime because of the potential of an armed victim. This arming effect is one of the reasons that the United States, only 10-12% of all burglaries are "hot" or committed while the victim is home (as opposed to the U.K. where Hot Burglaries make up 80% of the Burglarly rate). And even then, you do not need to own a gun to be defended by private ownership in the United States. All you would need is a bumper sticker slapped to your car in your drive way to make a criminal think twice about breaking and entering.
Keep in mind that this attitude goes way back to the founding of the country. The first battle of the Revolutionary War was because the British wanted to disarm their citizens living on what at the time was the edge of known civilization (they had already done this in Boston which angered the Bostonians, but not as much as the people who actually did use their guns for food and defense). The Second Amendment exists not because the government of the United States would do that, so much as it was that the previous government HAD DONE IT. In Europe, the only country close to the United States in this fear is Switzerland, though they never viewed their own government in this light (what with Direct Democracy and all that) but when every other country that shares a border with Germany is invaded, you do start to worry about fighting a tyrannical government.
I know I've thrown out a lot of numbers and what have you, but it's to show that numbers are not the only determinate factor at play. There are a lot of cultural factors at play as well, and the United States tends to have a population with a lot of voices from a lot of different parts of the world. It's not as simple as this one thing.