Monday, January 30, 2012

Do Guns Make You Safe?

Over on Facebook, a friend shared a story about an elderly woman who was pulled over. The officer discovered that she had a variety of guns in the car. (She had a permit.) The story ends with the woman saying that she's not scared of "a f***ing thing," the implication clearly being that it's because she has firepower at her disposal. A friend chimed in that there's "nothing for one's piece of mind that good, reliable piece of the gun maker's craft," to which I replied:
Yet, oddly, *not* owning a gun makes you safer, statistically speaking. Chalk one up for human irrationality!
I recall having read this statistic although I freely admit I can't remember the source, or any specific study that backs it up, which makes me wonder how true it may be.

The easiest way to frame the question is: Does owning a gun actually make you safer?

If people with guns are safer than people without guns, then the increased peace of mind is fully justified ... but are they?

Cause and Effect
First of all, let's be clear on what I said ... or, more specifically, what I did not say. I did not say that buying a gun, by itself, makes someone less safe. I said that statistically speaking someone who doesn't own a gun is more safe than someone who owns a gun. Even if the statistic is true, this doesn't mean that the gun itself is the cause of the decrease in safety. In fact, likely far from it.

For example, it's very reasonable to think that many people who have legitimate fears for their safety would go out and buy a gun, such as in the case of someone who has received specific death threats. In this case, the gun isn't the cause in the decrease of safety. These people are already in a situation where they're afraid for their lives, and the gun is an effect, not a cause, of the decreased safety. This is perfectly in line with my above statement.

Or, alternately (and probably more commonly), someone who has an illegitimate fear for their safety goes out and buys in a gun. As I will show, it's actually very unlikely that most people will be a victim of violent crime, so if you're afraid of being a target, it's probably a misplaced fear. In other words, I would argue that people who fall in this category are more prone to excessive amounts of stress over unnecessary things, and you're far more likely to die from stress-related causes (heart disease, stroke, etc.) than from a firearm, according to the CDC.

I suspect that the results of my analysis will say that guns do increase safety, but that's in part because I don't have the research capacity to actually look into all of the demographic information involved.

How Prevalent is Violent Crime?

The point is that a gun gives one "piece of mind," which presumably comes from the idea that the gun offers protection from potential harm. In other words, the gun is acting as insurance. If you are in a situation where a gun can protect you from harm, then this feeling might be perfectly justified.

According to the FBI's Uniform Crime Report, in 2010 there were 1,246,248 violent crimes. Here are other statistics from that report: 
  • There were an estimated 403.6 violent crimes per 100,000 inhabitants in 2010. 
  • Aggravated assaults accounted for the highest number of violent crimes reported to law enforcement at 62.5 percent. Robbery comprised 29.5 percent of violent crimes, forcible rape accounted for 6.8 percent, and murder accounted for 1.2 percent of estimated violent crimes in 2010. 
  • Information collected regarding type of weapon showed that firearms were used in 67.5 percent of the Nation’s murders, 41.4 percent of robberies, and 20.6 percent of aggravated assaults. (Weapons data are not collected for forcible rape.)
Using the 403.6 violent crimes per 100,000 inhabitants figure, if we assume that crimes are distributed randomly among the population, then the probability of being the victim of a violent crime is 0.4% in 2010.

Now, the intelligent reader will argue that there are no doubt more crimes than this, because certainly violent crimes happen which the police never learn of. I'll grant this point. In fact, looking at previous years shows that this is actually a fairly low rate even among the crimes that law enforcement knows about. (In 2008, for example, it was closer to 0.45%.) The Crime Victimization Survey 2010 indicates that 50% of crimes are never reported, but I'm assuming that the Uniform Crime Report includes all of these, not just the ones that are actually reported.

One other factor, which is harder to nail down, is about crimes that are completely averted because of the presence of a gun. In a 1994 study, criminologist Gary Kleck indicated that he believed (based on survey data) that somewhere between 800,000 and 2.5 million crimes were averted because of the presence of a gun. (Oddly, many of those citing him, including Wikipedia, reference only the 2.5 million number. Biased much?)

Still, we can assume that there are a fair number of crimes out there which take place if not for the presence of guns. For the sake of argument, let's assume that there's a real massive unseen sea of lawlessness out there, and in fact there are twice as many violent crimes (or attempted ones) as those that law enforcement officially included in their Uniform Crime Report.

Using our new, probably-high estimate, we end up with a 0.8% chance of a random person being the victim of a violent crime. Let's round up to an even 1%!

Demographic Considerations

I have, of course, vastly over-simplified things. Among gun-owners in America, the vast majority don't own guns for protection, but rather own them for hunting and other sport activities. And most of these people live in rural areas. (Reference: Gun politics in the United States, Wikipedia.) Therefore, the majority of guns are in rural areas, but the majority of crime is in urban areas.

Similarly, our previous (high) estimate of 1% was assuming that violent crimes are evenly distributed among the population, but that's almost certainly not true. Some people are more likely to be victims of violent crimes. People, for reasons both legitimate and illegitimate, end up in situations that make them more likely to become the target of a violent crime, such as:

  • convenience store clerks (robbery target)
  • coin shop proprietors (robbery target)
  • drug dealers (criminals / hang out with criminals / robbery target)
  • drug users (wrong place / wrong time / hang out with criminals)
  • money launderers for the mob (hang out with criminals)
  • people who steal from the mob (piss off criminals)
  • off-duty policy officers (revenge / piss off criminals)

You get the idea. Some of these people, legitimately realizing that they're likely going to be targets of criminals, are also likely to own a firearm. (My local coin shop, for example, features a prominently displayed handgun in easy reach of the clerk.) These people have a reasonable expectation that they may enter into a situation where there is violence, and where a gun might save their life, so they may well be justified in having an increased peace of mind. (I would argue, however, that their peace of mind could be increased even more by going into another line of work that lowers their risk of being assaulted.)

In fact, most of these people would probably be in a situation to be victims over and over again, which further throws off the statistical prediction (already very high) that the average person has a 1% chance of being the victim of a violent crime in a given year.

Do You Need a Gun?

In a given year, then, saying that there's an 1% chance that our hypothetical "average person" would be the victim of a violent crime is a very high estimate. If 25% of American adults own firearms (according to Wikipedia), that means that we have over 78,000,000 gun owners in the United States. Using these numbers, we would therefore expect that about 780,000 gun owners would be targets of violent crimes. Of course, many criminals are also gun owners, so these aren't necessarily going to be "innocent" people, but that's not really relevant to the analysis.
Note: This again throws the earlier statistics from Kleck into question. It's unrealistic to believe that 780,000 gun owners are able to prevent 2.5 million crimes a year by virtue of having their guns. Even the low estimate of 800,000 is highly questionable. This reassures us that we're making estimates that are skewed, if anywhere, in favor of gun ownership being beneficial. Of course, it may be that they're counting the deterrent effect of people like my coin shop owner having a gun on display, which I imagine does prevent people from being too stupid and trying to rob him on a whim.
However, are those 780,000 gun owners really safer? (For the sake of argument, we will assume that the gun owner is carrying their gun when targeted by a violent crime - yet another bias in favor of the gun owner.) It seems to me like violent attacks come in two varieties:

  • Attempts to do harm (possibly with robbery as a motive)
  • Robbery (with the intent to do harm if needed)

Based on the Uniform Crime Statistics, it looks like about 25% of the violent crimes are robberies. (Presumably if someone is shot and robbed, it would count as a murder, not a robbery, but that's not really clear from the report and I don't have the time to dive much deeper into the data than I already am.)

Therefore, it would seem that there will be about 535,000 direct assaults on gun owners with the specific intent to do them harm. In other words, the goal of the violent crime is murder, aggravated assault, or rape. Presumably these 535,000 people are able to prevent the assault, either by referencing the weapon, displaying it, or shooting the assailant. There may be a handful where the person only planned to beat the person up but they changed to murder when the victim pulled a gun, but I'm going to assume this is a negligible situation.

Now, on to robberies. Using our approximations, there are 195,000 people who are robbed while carrying a firearm. Again, the Uniform Crime Report indicates that firearms are used in about 42% of robberies, so we have 113,100 cases where the victim has "outgunned" the attacker and 81,900 cases where they're pulling a gun on a robber with a gun.

My assumption is that the average robber actually would prefer to take the money (or car or whatever) and run, without having to shoot anyone. Therefore, in these 81,900 cases, I'd say that the person pulling the gun has actually now escalated an already bad situation, and probably increased the likelihood that someone - possibly themselves - will be shot. I have no reasonable way to evaluate how these scenarios typically play out, so I'll just call this a wash: let's say there's a 50/50 chance a person in this situation comes out without being shot. However, if they had just handed over their wallet, I'm assuming the robber would have left, which means that the ownership of a gun has increased the chance that you'll be shot in about 40,000 cases.

We'll assume that the robber without a gun surrenders or runs away, although there is a possibility of the gun owner being stabbed while going for the gun or that the robber tries to wrestle it away or something.

So, in other words, using these assumptions we have the following results:

  • 40,000 cases - gun owner escalates the situation and gets hurt
  • 740,000 cases - gun owner prevents a violent crime

Certainly, it does look like (on average) if you are going to be the victim of a violent crime, then you come out ahead if you're carrying a firearm. That's to be expected, of course, so it's nice that our estimates have confirmed intuition.

Now, though, let's keep in mind the various pro-gun ownership assumptions needed to reach these numbers:

  • A high probability of being a target of violent crime, evenly distributed randomly among the population.
  • All gun owners possess a gun appropriate for personal protection
  • All gun owners always carry the gun (or at least when being victimized)
  • The vast majority of gun owners are successfully able to use the gun to thwart the crime (except for the handful who I assume escalate danger during a robbery)

But what about the rest of the population?

The 99%

Our various pro-gun assumptions do have consequences for the rest of the population.

Specifically, we are now assuming that there are 78,000,000 gun-owners who are continuously within arm's reach of their firearm at any given moment. For one thing, this means that every criminal who owns a gun is always carrying it with him, which means our earlier estimates of the number of gun-related crimes was likely fairly low.

In 2004, the CDC reports a total of 750 accidental shootings of various types and around 18,700 suicides by firearms. The low shooting rate is likely in part because most people keep their guns (which, remember, are mostly used for hunting and other sporting activities) safely stowed, locked up, and unloaded, the vast majority of the time.

I think that even pro-gun advocates would agree we don't want all gun owners to have guns quite this accessible, and that doing so would likely increase the amount of gun injuries and deaths. Even if you assume that all gun owners are proficient in handling their gun, and you assume that there's a 1-in-a-million chance that an experienced gun-owner has a mishap that results in injury, you end up the following:

78,000,000 gun owners handling guns 3 times a day (at least) for 365 days a year = 85,410,000,000 gun interactions

Even a one-in-a-million chance of accident is going to be bad in this firearm utopia, resulting in:

85,410 gun accidents a year.

Still, the 740,000 hypothetical violent crimes that have been prevented are more than enough to probably justify these 85,410 gun accidents.

As I said at the beginning, though, these statistics have been fairly easy to find or extrapolate, but what's a lot less clear is the hidden correlation. Do gun owners stress out more or less than non-gun owners? What other demographic trends are there? Does the gun-owning population live more high-risk lifestyles, either in legitimate ways (hunting) or illegal ones (drug dealing)?

So, in short, it looks like guns may make you a bit more safe ... but the real takeaway from all of this research is, for me, that you really weren't that unsafe in the first place!


Philip Brewer said...

Suicides are the main way that owning a gun may make you less safe, because having a gun to hand makes suicide attempts much more likely to be successful.

Oh, and you left out hookers in your list of people who are prone to being the victims of violent crimes.

If you're not a hooker, not a drug dealer, not a violent criminal, and not suicidal, the risk that you'll get shot is incredibly small.

Anonymous said...

That is probably true but I'm buying one anyway. The chances of a Katrina like disaster are a possibility where I live and I saw how that went down. Your statistics come from a law abiding society. I think that might change.

Anonymous said...

A couple points. The discussion centers on the gun owner feeling safer. I'm not half as concerned about a criminal attacking me with a gun, though it has happened, than I am the crazy neighbor down the block, or the swaggering kid with a gun. The more fearful you are, the more paranoid, the more you see threats around you, the more likely you are to seek assurance from a weapon, and then shoot first - just to be safe. Having carried a gun on a job I noticed a reaction in myself that surprised me; cockiness. I was just waiting for someone to try something, and I detest guns (not weapons, BTW, just guns). As to the deterrent effect, such as the guy with the gun behind the counter, or in their night stand; wishful thinking? The criminal is not going to wait while they get it? First gun out, wins, period, and by the nature of crime, that's the criminal's. If in your panic to "protect" yourself you reach for it, or he even thinks you might be reaching for a gun, the criminal's options are reduced to shoot, stand and be shot, or run and be shot.