Gun Control: How would we know?



I don't know how to keep this topic away from , so I'm just going to exhort everyone to try to keep this about rationality and not about politics as usual.  I myself have strong opinions here, which I'm deliberately squelching.

So I got to thinking about the issue of gun control in the wake of a recent school shooting in the US, specifically from the POV of minimizing presumed-innocents getting randomly shot.  Please limit discussion to that *specific* issue, or we'll be here all year.

My question is not so much "Is strict gun control or lots of guns better for us [in the sole context of minimizing presumed-innocents getting randomly shot]?", although I'm certainly interested in knowing the answer to that, but I think if that was answerable we as a culture wouldn't still be arguing about it.

Let's try a different question, though: how would we know?

That is, what non-magical statistical evidence could someone give that would actually settle the question reasonably well (let's say, at about the same level as "smoking causes cancer", or so)?

As a first pass I looked at and and I noted that the US, which is famously kind of all about the guns, has significantly higher rates than other first-world countries.  I had gone into this with a deliberate desire to win, in the less wrong sense, so I accepted that this strongly speaks against my personal beliefs (my default stance is that all teachers should have concealed carry permits and mandatory shooting range time requirements), and was about to update (well, utterly obliterate) those beliefs, when I went "Now, hold on.  In the context of first world countries, the US has relatively lax gun control, and we seem to rather enjoy killing each other.  How do I know those are causally related, though?  Is it not just as likely that, for example, we have all the homicidally crazy people, and that that leads to both of those things?  It doesn't seem to be the case that, say, in the UK, you have large-scale secret hoarding of guns; if that was the case, they'd be closer to use in gun-related homicides, I would think.  But just because it didn't happen in the UK doesn't mean it wouldn't happen here."

At that point I realized that I don't know, even in theory, how to tell what the answer to my question is, or what evidence would be strong evidence for one position or the other.  I am not strong enough as a rationalist or a statistician.

So, I thought I'd ask LW, which is full of people better at those things than I am.  :)

Have at.