A piece in Slate is titled The Irrational 18-Year-Old Criminal. Its subtitle is: “Evidence that prison doesn’t deter crime.”
That headline should have you chuckling. But you’ll chuckle even harder if you read the article and understand the pseudo-science forming the evidentiary basis for this ridiculous conclusion.
If the only point of the article were to discuss the possible effect of increased penalties on criminals, that would be one thing. But the study described in the piece, as it is described, doesn’t even come close to supporting the broader claim that “prison doesn’t deter crime” as to society at large.
Details in the extended entry.
The article says:
Both the prospect of getting caught and the prospect of spending time in prison are supposed to deter forward-looking, rational potential offenders from criminal activity, encouraging more-constructive pursuits like staying in school or at least making French fries. More mechanically, prison also prevents crime by simply caging dangerous people. Deterrence has long been an article of faith among economic theorists and, more recently, economists who do empirical work, too. But now a series of careful studies by economists at Columbia and the University of Michigan are calling into question whether either policing or punishment successfully deters crime.
The methodology is laughably flawed, because it doesn’t just look at “potential offenders” who might be deterred, but rather only at actual offenders who haven’t been deterred:
David S. Lee of Columbia and Justin McCrary of Michigan . . . noted that when kids turn 18, they suddenly face much stiffer adult sanctions. Then they got access to data on all felony arrests in Florida between 1989 and 2002. Each arrest links to an individual, whose birth date is included in the data. This allowed the researchers to create an arrest history for each person arrested and to measure the effect of turning 18, and thus facing longer prison terms, on criminal activity.
Note clearly: the pool of people in the study includes only people who have been arrested at least once in their life. Looking at these people only, the economists found that the possibility of greater punishment at age 18 had no measurable effect:
In Florida during the years in question, Lee and McCrary found, the probability of being sentenced to prison for an offense jumped from 3 percent to 17 percent at exactly age 18. This tees up the answer to the economists’ main question: How does the tendency to commit crimes vary around the 18th birthday, when the odds of a prison-sentence punishment jump? The answer is, hardly at all. While the probability of being arrested each week falls steadily from age 17 to age 19, there is no sizeable decrease in the arrest rate that corresponds to the bump up to an adult penalty in the weeks before and after people turn 18.
By restricting the subjects to people who have been arrested at least once, the economists skew the results — apparently without even realizing it. Unlike people who have never been arrested, people who have already been arrested have already proven that they are less likely than the average person to be deterred by the prospect of incarceration to begin with.
If these economists really wanted to look at how the threat of incarceration affects deterrence, they should look at the whole population. Instead, they focus precisely on the pool of people least likely to be deterred — a pool that has already proven that, in the past, the threat of incarceration did not deter them from behavior that caused them to be arrested.
By analogy, if you wanted to find out whether flu shots work, you would establish a control group of people who did not get flu shots, and compare it to a group that did, to see who ended up getting the flu. The goal would be to determine what effect flu shots would have on the entire population of people who got a flu shot. The approach described in the article, by contrast, would be like restricting your experiment to the subset of people who had a flu shot, but got the flu anyway — and then giving them two flu shots, to see if administering more flu shots will work better. The logic goes like this: if two flu shots don’t work any better than one, then, by God, flu shots must not work at all!
This “logic” would be flawed because it would completely ignore the people for whom flu shots do work.
Similarly, this study ignores the very people who are most likely to be deterred by the possibility of incarceration: people who are, in fact, deterred to begin with — to the point that they have never gone and gotten themselves arrested. Those people don’t figure into the study in any way that I can tell.
Restricting the study to people who commit crimes — or at least get arrested for them — magnifies the distortion caused by another problem with the study. This problem is a common one among studies by economists: the assumption, made by so many economists, that the players involved have perfect information. This is such a common character flaw among economists that it is the basis for many jokes, one of which goes something like this:
An old joke has an economist and a trader walking down the street. The trader says to the economist: “There’s a $20 bill lying on the sidewalk.” The economist replies: “No there’s not.” The trader responds: “But it’s right there!” “No,” the economist patiently explains, “if there was a $20 bill lying there someone would have picked it up already.” At this point, the trader leans down, picks up the $20 bill and they continue on their way.
The point is simple: economists measure human behavior by assuming perfect information on the part of actors. This is a generally useful assumption for measuring economic factors. However, it can become problematic if you forget that it’s not realistic. It can be especially problematic if you’re examining a group consisting of people who are less likely than average people to have good information — or to use it when they have it.
As a general rule, that is a good description of people who get arrested for crimes, which is why it is dangerous to extrapolate their behavior to the entire population.
The criminal defendants I see tend to have a poor understanding of the potential consequences of their behavior, at the time they engage in the behavior. What’s worse, even when they do have this information, they often ignore it. If there is one characteristic that is widely shared by people who face criminal charges in the courthouse where I work, it is that they tend to have very poor judgment. That’s what caused them to commit crimes to begin with. It’s what caused them to get caught. And often, it’s what causes them to take actions that are clearly not in their own best interests.
It is always a risky thing for scientists to assume perfect information is held by any group of people. But it is especially risky for them to assume that perfect information is held by people who get arrested for crimes. And it is foolish to look at the decisions made by those people, and to extrapolate them to society at large, and to assume that people who have never been arrested would react in exactly the same way to the possibility of incarceration.
Yet that’s exactly what these economists appear to be doing, based on the description provided in the article.
The problem gets worse when you’re looking at juvenile criminals who are turning into adult criminals. Anyone familiar with the juvenile criminal justice system knows that, whatever its benefits might be, it is not a system that teaches young criminals that crime has consequences. Arguably, it has the opposite effect on many a young offender. A typical 14-year-old caught stealing a car or breaking into a business is going to be sent “home on probation” with instructions to obey Mom and Dad and get good grades. You have to work really hard to get yourself confined at the next level of publishment, which is literally called “camp.” Only the very worst of the worst get incarcerated at the California Youth Authority. These are the kids who commit the violent crimes, often involving firearms or serious violence, and/or kids who are so undisciplined that they can’t function at home or in “camp.”
The juvenile justice system is so lenient in California that, if you are 13 years old, you can murder as many people as you like, as brutally as you like, with absolute premeditation — and you cannot by law be incarcerated past your 25th birthday. Even if you are a serial rapist-murderer with 30 victims, all of whom were horribly tortured, the state must let you go at age 25.
When one of these young thugs turns 18, they often have a short lifetime of crime under their belts already — and distressingly often, it’s a lifetime that has resulted in no consequence that a rational person would say fits the crime.
Now when they turn 18, if they commit a stick-em-up robbery with a gun — something that might have gotten them “camp” at one point in their life — they’re looking at 12 years in prison at 85%. And that’s if they plead guilty. It may be more if they go to trial.
Did these kids know they would be facing this kind of time? Did they have “perfect information”? In a lot of cases, I think they didn’t. And even if they did — even if someone once told them that things would be different at age 18 — they weigh that abstract knowledge against a lifetime of having received minimal punishment for their crimes. In that context, they may pay no attention to their abstract knowledge that consequences get worse when you’re an adult.
Does it make sense to look at the behavior of people with that sort of background, and extrapolate it to society at large, to conclude that prison does not deter criminal behavior by the average citizen? Of course not. Your average citizen is much closer to having perfect information than these new adults who just finished a juvenile life of crime. Your average person knows that armed robbery will result in a stiff prison sentence. These young criminals often don’t. They’ve had a lifetime of being taught that the punishment is never really that bad. I bet a lot of them are shocked to learn that they’re really facing 12 years for an armed robbery.
Now, once they’ve actually served their first adult sentence, they may be closer to perfect information. Maybe the study should look only at second-time adult offenders who have already experienced adult consequences for crimes committed as an adult. But it would be very hard to take important variables into account in a study. You’d have to control for a disposition to commit serious crimes — a disposition that may be unrelated to the question of whether they will face significant time in custody. After all, someone who commits an armed robbery may well have other problems in their life that outweigh their ability to rationally weigh the consequences.
But the fact that this is true of someone who has already committed one or more crimes doesn’t mean that it’s true of everybody. Plenty of people might be on the fence morally about whether to commit certain crimes, and may decide that the prospect of incarceration is enough to deter them. Some of those people might be minimally deterred by lesser punishments and more so by greater punishments. But you can’t draw these conclusions only by looking at people who have been arrested. Those are the people who aren’t getting deterred anyway.
If the point of the article is that criminals tend not be be deterred by greater punishment, there may be some minimal value to the study — though, like almost all criminal justice studies, the controls are almost certainly inadequate to reach even that modest conclusion.
But to say that the study provides “[e]vidence that prison doesn’t deter crime”?
Give me a break.
P.S. Sorry this post was so long. As the saying goes, I didn’t have time to make it shorter.