Friday, February 12, 2016

Brain dump on gun control, and why I'm skeptical of it

I've long been uninterested and agnostic on gun control. I'm not sure why it generally hasn't interested me, since I like politics. But I was agnostic largely because I had the impression that studies on it were really inconclusive. Then a couple months ago, the two widely covered shootings ramped up the issue. Obama even said inability to pass new gun control laws has been his "biggest frustration". This awesome NY Daily News cover happened. And I got a small burst of interest in the topic, looked into it a bit, but have ended up mostly where I started. Here's a brain dump on what I learned and what my thoughts are. If I feel like digging into gun control again in the future, this will help me pick up where I left off. Or maybe this will prompt a discussion that will help clarify some things for me.

Common misconceptions about gun violence

"Violence is getting so much worse!"

In reality, the U.S. and the world has seen declining violence, both over the course of history and our lives. Here's gun violence over the past several years in the U.S., from the Pew Research Center:

Gun Violence Has Declined Since '90s

Yep, gun homicides are down by half since 1993.

It is true, however, that homicide is unusually high in the U.S. compared to other developed nations. Check here for the numbers.

"But mass shootings are increasing, and that's what's most important!"

I don't know how to determine if that's true because there's not a clear line between "mass shooting" and regular shooting. Depending on where you draw that line, you can get very different results. Read this. Regardless, mass shootings are a very small share of all shootings. We should want to stop shootings because being murdered is bad. Five separate single-person murders are worse than one four-person murder. Giving all our attention to the latter case is a misleading distraction, and maybe a dangerous one. There's some reason to believe that our extra attention is part of what inspires deranged people to commit those shootings in the first place.

"All this gun violence is really about mental illness"

This seems like a wishful-thinking argument that attracts people on both sides of the gun debate. Some on the right would like this to be true because it means guns aren't the problem. Some on the left would like this to be the case because it's nice to believe all the world's problems will go away if we just provide more care to those in need. But... "only 3%-5% of violent acts are attributable to serious mental illness, and most do not involve guns." -- source

Common Facebook-level pro-gun arguments

"We need our guns to defend against the government."

We have, by far, the largest and most funded military in the world. If for some reason I need to take up arms against the government, that will be why I will fail, not because of more stringent background checks or more limits on what types of guns are legal. Strangely, most people who use this argument also want to increase our military, which keeps me from taking this very seriously.

"Guns don't kill people; people kill people."

I don't even know what this means. "Nukes don't kill people; people kill people." Does anyone ever say that? Why not?

"Criminals don't follow laws, so laws restricting guns won't reduce gun availability for the bad guys."

A simple counter-example is grenades. It's not legal for us to buy grenades, for the good reason that we don't want it to be very easy for a person to kill a whole lot of people. And yet we don't see many criminals using grenades to commit mass murder. In recent mass shootings, where the attacker wanted to kill many people, they tend to use legally-acquired weapons. Making something illegal usually reduces its occurrence... otherwise I'm not sure there'd be any point to having laws.

However, the counter-counter-example is alcohol and drugs. Clearly, a restrictive government policy of a high-demand product (like the Prohibition) can create black markets, which can make the law ineffective as well as create even more problems (like better funded criminal organizations). So I do think this has to be in the "potential cons" list when considering any proposed gun law.

"The only person that can stop a bad guy with a gun is a good guy with a gun."

This is the idea that less murders would happen if more people had guns, because potential victims could defend themselves. This is a hard thing to judge because I don't think there are good numbers on how many murders are prevented because the would-be victim had a gun.

One starting point is the number of "justifiable homicides" each year, since the FBI keeps track of that. A "justifiable homicide" is when one person kills another, but is cleared from wrong-doing because it was in self-defense. That looks to be ~275 per year on average.

On the other hand, a good guy with a gun can also cause gun accidents. The CDC gathers data on gun accidents per year, and in the most recent year I saw, the numbers were 505 deaths and 33,636 injuries.

Another potential downside to good-guys-with-guns is escalating a crime. For example, an armed robber who only intends to rob a person without harming them may shoot the victim once realizing that the victim has a gun. I have no idea how to get an idea for how common this happens though.

So we have some positives and negatives to good-guys-with-guns. Surely many crimes are prevented by the bad guy's knowledge or just suspicion that the would-be victim is armed, so the number of crimes prevented by good-guys-with-guns has to be much more than just the number of "justifiable homicides". But I don't know how we'd get a very good idea of how big of a factor this is beyond that. Maybe it's enough to offset the negatives, or maybe not.

And if you want a funny take on this, here is a Daily Show correspondent who went through a simulated shooting to see how well he'd be able to stop the killer.

The Evidence

So if you want to know what affect gun control actually has in the real world, it's probably best to look at empirical studies done on... gun control in the real world (actual academic studies, not "studies" from political groups with a pre-determined agenda). It turns out that most studies focus on gun ownership rates. They are a simple way to measure the size of the change from a gun control law. And most gun control arguments largely boil down to the idea that making it harder to get a gun would reduce gun deaths; if that's true you'd expect to find a correlation between gun ownership and gun violence.


I started by looking at the studies on the gun laws that passed in Australia after their mass shooting in 1996, because that's what I've always heard about as the most drastic change in gun policy, and presumably that means its effects on gun violence should be easiest to detect. It did lead to a significant decrease in gun ownership (30%!), and a lot of research has been done on its effects on gun violence.

Here is the most recent study, which also gives an overview of previous studies. Its methodologies do not find a statistically significant change in homicide or suicide rates from the law. And here is the study most commonly cited that does suggest the law reduce homicide and suicide (it finds the reduction on suicide is much bigger/clearer than the reduction on homicide).

I'm not smart or knowledgeable enough to judge which of those are better. And from what I can tell, researchers themselves are fairly split on it as well (otherwise I would just go with the consensus of the experts). I have gotten the impression though that there's a bit more agreement that the evidence gives good reason to think it reduced suicide by a decent amount.

I'll go with the average of the expert opinions here and take this as evidence for a small positive effect from the gun control law in Australia on homicide. It's worth noting that the divide between the researchers/studies are between "good" and "neutral" effects; nobody is seriously looking at the evidence and finding that Australia's gun control made violent crime worse.

The U.S.

From a first glance at the U.S. compared to other developed nations, gun ownership and homicide look clearly correlated. The U.S. has more homicide than similar countries and way higher rates of gun ownership:

But from a first glance at states within the U.S., you see a small negative correlation; states with more guns have less murder:

Of course, since crime rates are influenced by a wide combination of things, this divergence shouldn't be too strange as long as you accept that gun ownership is just one small variable of many. So what do empirical studies in the U.S., which try to isolate the variable of gun ownership, say? From what I can tell, they are pretty mixed, and a quick overview can be seen here. That linked paper also talks about common problems with gun studies, and claims that the studies that do a better job at avoiding those problems are less likely to find a statistically significant correlation between gun ownership and gun violence.

But at Slate Star Codex there's a really interesting dive into one study that looks to be particularly good, which works out a framework for predicting homicide that works when run in different ways, and does find a (small!) correlation between gun ownership and homicide. And it's far more interesting than anything I can write about this, so you should probably just stop wasting your time here and read that instead.

Things I worry about

All the above makes me lean toward believing that less guns would mean a little less murder, while still mostly being agnostic. But there are things that make me worry that trying to legislate/enforce our way there would backfire...

1. Trying to pass gun control can increase the number of guns.

Whenever there is even the perception that new gun control laws are likely to pass, gun purchases go up. So if politicians try and fail to pass new gun laws, they have caused the opposite of what they hoped. And even if they succeed, the increased purchases may be more than the decrease that the law brings into effect.

2. The U.S. may be more prone to a black market if restrictions get too tight.

Australian gun control measures did not produce a big black market with all the problems that can bring, like we currently have with drugs. But Australia passed their laws with widespread public support, as well as with a previous gun ownership rate of only 7% (compared to 32% here). Clearly, any change in America would have less widespread support, and guns are a much deeper part of our culture.

3. The U.S. already has too many guns to make any difference without a drastic change.

Consider the difference in gun ownership between the U.S. and Canada (getting the numbers from which I already linked earlier). The U.S. has 4 times as many guns per capita as Canada. But our gun ownership rates are not nearly so different: 32% here and 26% in Canada. This must be because Americans who own guns tend to own many guns. The ease of access to a gun has more to do with ownership rates, not guns per capita. But gun control measures will tend to be working on guns per capita, and in the U.S. you could greatly reduce the guns per capita with basically no effect on ownership rates.

4. Gun control would take effort that'd be better spent elsewhere.

Even if, despite all these problems, gun control would be overall good, there's a good case that it'd be only a tiny bit of good relative to the effort and likelihood to make meaningful change. There's a theoretical list of all the things our government could do differently, and they should be fought for in an order prioritized by amount-of-good times likelihood-of-happening. Even if gun control is on that list, maybe the effort spent on it is keeping people from working on something higher up that list.

5. Enforcing stricter gun control laws could increase tension between the police and African American communities, and thereby increase crime

As touched on by the slatestarcodex link I provided earlier, the main reason for high homicide rates in the U.S., relative to other developed countries, is cultural. In particular, African Americans account for a disproportionately high amount of the violent crime. I believe in Steven Pinker's explanation of violence as explained in The Better Angels of our Nature. In the case of this topic, the applicable part of his ideas are that violence within a community is correlated with distrust of those who have a "monopoly on force" (the police). We have a particularly bad history in our country between the police and African Americans, and this explains the higher violence. It's easy to get stuck in a vicious cycle there where that higher violence brings a harsher police presence, which maintains the distrust of police, and so on.

If that is the case, then the most important thing to do is to rebuild trust, although that's not quick and easy. Arguably the biggest thing we can do toward that end is reduce unnecessary conflict with police by reducing the number of things the police should enforce. This is why I think ending the war on drugs would go a long way toward reducing violent crime. But if there were a very big effort to enforce much more restrictive gun laws, you can expect it to be enforced much more harshly in poor minority communities.

6. How much value should freedom be given?

Earlier I linked to the CDC's numbers of accidental deaths by different causes. You know what had far more deaths than accidental shootings? There were 3,391 deaths by accidental drownings. Suppose we can reduce those with "swimming pool control" laws. Should we? Or would you feel like that's an encroachment on people's liberties that wouldn't be worth the lives saved?

What could make up my mind?

Gun suicides kill twice as many people in the U.S. as gun homicides, so arguably this should be the focus when trying to determine the effect of gun control laws. And my impression is that there's a stronger link between the two in the evidence, but I haven't looked into it as much. So this is a point currently in favor of gun control, but I'm really not sure what sort of value to place on that relative to other things. Learning or thinking more about this could change my mind on the issue.

On homicide as well, learning more about evidence on that could definitely change my mind either way since I've barely scratched the surface. But I'm too bored to go on, and not optimistic about what value I'd get out of further digging.

Or maybe future evidence with better information that doesn't yet exist will clear everything up. Speaking of which... for political reasons the CDC has not been doing gun violence research for a long time. That's probably not helping.

There's also countless possible ideas that could be called a "gun control law" that this general overview doesn't address. Surely some would be good and some would not. I just don't know which is which, nor am I familiar with all the different types of gun control that have been proposed. Maybe looking at more specific proposals will sound convincing to me and not be prone to the concerns I have. Or maybe not.

The end.