One of the most irritating tendencies of people on the right is to accuse people on the left of “not understanding basic economics.” This usually comes when lefties advocate that the rich give up a bit of their wealth to aid the poor, or when we point out that capitalism has an unfortunate habit of making everybody’s lives revolve around the desperate quest for financial security. The “you just don’t understand economics” attack is particularly unfair because it fails to consider the possibility that people on the left understand economics perfectly well but have good reasons for rejecting certain economic premises.

Thus I have mixed feelings about doing a “you don’t understand economics” argument myself, because I recognize it’s inherently supercilious and involves casting others as idiots rather than people with reasonable disagreements. Still, I can’t resist the opportunity to give the right a heaping spoonful of its own toxic medicine. Therefore: certain arguments favored by gun-rights advocates are woefully ignorant of basic economic insights.

The arguments in question are those along the following lines: efforts at gun control are senseless, because people will always find ways to kill each other. Or, in its bumper-sticker form: when you outlaw guns, only outlaws will have guns. And the basic economic insight that these arguments ignore is: people are rational actors who respond to changes in incentives.

The “outlaws” argument is among the oldest and most incessantly-repeated clichés in the discourse around guns. In the past couple of days, I’ve seen it flare up again on social media in conversations surrounding the recent London terror attacks. First, gun control proponents began citing the attacks as evidence of why strict gun control measures are useful: because large-capacity firearms are difficult to obtain in the U.K., unless an attacker has pretty sophisticated knowledge of explosives manufacturing, they will generally have to resort to using knives and vans rather than AR-15s. The same point is made about would-be mass-murderers in China: when, for instance, a madman in Zhongyuan decides to go on a violent spree at a primary school, a lot of kids might get stabbed, but as often as not they will all survive. If the same thing happens in Connecticut, there will be dozens of deaths. Madness is madness, but guns make killing people as simple as pushing a button.

In response to this, I’ve seen gun rights supporters making the “futility” point: if the British attackers had wanted to use firearms, they still could have. There are black markets, and just as Prohibition didn’t get rid of alcohol but simply drove its use underground, guns will always be available to those who want them enough or have enough ready cash. France’s gun control laws, for instance, did not stop the Bataclan terrorists from massacring nearly 100 Eagles of Death Metal fans.

The “outlaws” slogan also offers a variation on this theme. However, the slogan has two components, which should be distinguished: first, if you outlaw guns, that only outlaws will have guns, i.e. that law-abiding citizens will be deprived of guns for protection, and second, that outlaws will have guns, i.e. that “bad guys” don’t care about laws anyway. At the moment it’s the second claim that I’m interested in: that laws don’t stop the outlaws.

I don’t think I’m misstating or exaggerating the thrust of the argument put forth by gun rights advocates. While there may be more sophisticated versions, I certainly do see a lot of arguments, both in person and online, that come down to the idea that you simply can’t stop people from having guns, because if someone is determined enough to shoot someone, they will find a way to do so.

And here’s where the economic principle comes back in. A core insight of economics is that it makes sense to conceive of people as acting, in some sense, rationally, and calculating the relative weight of various preferences. And people tend to respond rationally to changes in prices; as things get cheaper, people will buy more of them, and as things get more expensive, people will buy less of them (assuming all other factors being equal, which they rarely are but nevermind that for now). Raise the cost of acquiring something and fewer people will acquire it. Raise the cost enough, and only the most determined people or the most wealthy people will acquire it. For each individual, there is a certain point at which the cost of something becomes too high. If I see a paisley-patterned dressing gown in a shop window, it will probably have to cost a lot for me not to buy it, because I am a sucker for both paisley-patterned goods and dressing gowns. However, if my friend Sparky sees one, such an item would probably have to be near-free for him to even consider buying it. They might even have to pay him to take it. This is because Sparky has taste.

I am sorry for dwelling on such an elementary principle, but it’s important for understanding why the gun argument is so mistaken. That’s because gun-rights proponents are misunderstanding how economic reality works. When a person evaluates whether or not to shoot someone, the question is not whether they can access a gun. The question is how high the cost of accessing a gun is, and whether that cost is worth it for that individual. If the cost of acquiring and shooting a gun is very low, then a lot of people are likely to do it who would not have done it if the cost was extremely high. Of course, many people won’t shoot anyone no matter how low the cost of doing so is, just as incredibly vicious and determined people would shoot someone even if doing so required exorbitant expense. (There is still a limit, of course: if shooting someone required more wealth than any human being possessed, then no human being would shoot any other human being.)

There is therefore actually a good deal of sense to Chris Rock’s amusing “$5,000 Bullet” proposal. Rock suggested that instead of gun control, there should be “bullet control,” because “if a bullet cost $5,000, there’d be no more innocent bystanders.” Rock’s routine is funny in part because it’s totally right. It seems absurd, but if you raised the cost of murdering people, fewer people would get murdered.

That runs counter to what we might think of as “common sense,” which would tell us that murderers want to kill people, and if they’re determined to do so, they’ll do it, and they aren’t sitting down and looking at spreadsheets trying to determine whether murder is a good long-term investment. The crucial economic insight is that actually, murderers are “determined” to differing degrees, and marginal increases in cost can actually act as deterrents. If you put few legal restrictions on gun purchases, for instance, but put the only gun store at the top of Mt. St. Helens, with a nine-hour queue, I bet you anything you’ll see fewer people buying guns.

It’s bizarre to think of all murderers, even crime-of-passion ones, as being in some way “rational,” and the economic argument for humans as “rational calculators” is generally heavily criticized on the left. But while I think many popular versions of the “humans as rational” argument are indeed ludicrous (the one that suggests we all maximize our financial self-interest, and the one that human beings never make stupid decisions, for instance), there is a version of this model of human behavior that makes a lot of sense. Human decision-making is both rational and irrational: it is rational, in that human decision-making does tend to look like a kind of weighing of costs and benefits. (For instance: I want a croissant. But it is raining. Does the amount I want a croissant outweigh how much I hate getting wet?) But it is irrational, in that many of our preferences are crazy and inconsistent and we aren’t good guardians of our own self-interest. The relative ease of killing someone might well affect whether or not a murderer chooses to do it (which means murderers are deciding whether or not to murder based on how difficult it is to do so), but on another level it’s totally irrational and crazy for “whether a gun is 10 feet away” versus “whether a gun is 100 feet away” to affect whether or not I take somebody’s life.

In practice, though, this is exactly what happens, and it’s easy to see why it does happen. We can think, using common sense, that people who want to kill people will always find a way to do so. But what actually happens is that if you raise the costs of something sufficiently, fewer and fewer people will do it. An effective, though heinous, way to reduce crime is to have “instantaneous death” as the penalty for every single crime, no matter how minor. Sure, there will always be the determined, foolhardy, or irrational few who do things regardless of the risks. But most people respond somewhat rationally to incentives. (This is also an important reason why proponents of drug legalization should be careful about invoking Prohibition. Depending on how it’s done and what the society is like, it could actually be correct that legalizing drugs will massively increase their use, because a subset of people who were deterred by the risk and inconvenience of criminalized drugs will try them once there are fewer costs to doing so.)

In fact, to successfully deter people, you don’t even need “most” people to be rational. You just need a subset of people. The question about gun control, then, is not: “Will it still be possible for outlaws to get guns?” but “Will gun control raise the costs of obtaining a gun to the point where a significant subset of outlaws are deterred from acquiring guns?” It’s not about whether you’ve created some kind of “absolute” barrier to the possession of weapons; it’s about whether you’ve added enough layers to where a lot of people will simply give up. The relevant question is not “Did the Bataclan attackers manage to obtain guns despite France’s gun control laws?” but “Do France’s gun control laws raise the costs of acquiring guns to the point of preventing certain deaths?” The easier you make guns to acquire, the more people will acquire them, as evidenced by the fact that in America there are twice as many gun stores as there are McDonalds’, and we spend large portions of our spare time using these guns to murder one another. 

You’d think people would do the same thing, regardless of adjustments in the incentives. But the economic insight is that actually, depending on what the incentives actually are, they won’t. They may be determined, but there’s a limit to their determination, and the point is to find that limit. I’ve made the same point about suicide before. The common-sense view is that no matter what, suicidal people will always find a way to kill themselves. But actually, that’s not true. The easier suicide is, the more people will do it. If you put a net beneath a suicide bridge, some people will still just go and find another high place. Others won’t, though; there is actually a pretty low threshold of inconvenience at which a person will just give up on killing themselves. (It’s actually stunning how much minor inconveniences will prevent us from doing things. Another example of how we are both rational and irrational: we’re rational because we’re clearly weighing alternatives, but irrational because why on earth would your decision to take your life vary based on whether you happened to think of a nearby bridge or have a gun in the house?)

I’d like to emphasize that I haven’t advocated any particular gun control measures here. In fact, I am generally a skeptic of gun control laws, because I am dubious about measures that increase the reach of the criminal justice system and will lead to more prosecutions. Prohibition can definitely work, but it might only be able to work if you institute an intolerably draconian system, and I am generally more interested in eliminating gun culture than toughening gun laws. But I am nevertheless committed to seeing a world without guns, and I am concerned with having (if such a thing is possible) a more sensible conversation around restrictions on their purchase and use. The question is not: can people find ways to kill each other despite restrictions, or can outlaws still find guns? The question is: will they, and what would make it so that they wouldn’t?