Make a simple statistical argument, get a simple statistical answer

The United States has 4% of the world's population and 50% of the world's guns.

— Morgan J. Freeman (@mjfree) May 17, 2022

Mr. Freeman is stating the fact that the US has 4% of the world's population and 50% of the world's guns.  There is an implication that that disparity has some significance and it is probably not too much of a reach to assume that Freeman is arguing that guns cause violence, and that the US is particularly violent because it has so many guns.  

Taking that as the presumed argument, is he correct?  Does the US have an excess of crime compared to the world because it has an excess of guns?  To make the claim simple and quick to check, let's assume that crime is detectable through murders.  

The obvious question is, what percentage of the world's murders does the US have?  It is very much a sloppy framing but the implication of the tweet is that more guns would equate to more violence and/or crime and/or murders.  

You quickly get into definitional issues and data quality concerns but a simplistic back-of-the-envelope calculation yields an answer.

Interestingly, the US has (17,284 US homicides/464,000 homicides around the world) 3.7% of the world's murders despite having 4% (technically, 4.3% [325m/7.6 bn]) of the world's population and 50% of the guns.

3.7% of the murders occur in a country with 4.3% of the world's population who also happen to have 50% of the world's guns.  

The obvious implication is that a prevalence of guns suppresses the murder rate.  A simplistic conclusion from a quick data check on a stupid observation.

There are all sorts of definitional issues, data quality issues, and contextual and confounding factors to be addressed before one could reach any sort of conclusion but it certainly calls into question the glib argument being made.