Epistemic status: highly uncertain
As of 2013, 2,220,300 adults were incarcerated in US state and federal prisons and county jails.
The majority of these people –about 60% — are incarcerated for nonviolent offenses such as theft, drugs, or public order violations.
How bad is this, in terms of years of life lost? How much damage is due to being imprisoned? (ETA: of course, in this context, I am only looking at the harms of prisons, not the benefits due to the deterrent effect of prisons, or the harms of crime. This should not be read as a claim that prison has zero deterrent effect!)
One article attempts to quantify:
African American males can expect to spend 3.09 years lifetime in prison, on average, and Hispanic and Caucasian males will spend on average 1.06 and 0.50 years, respectively.
Comparing life expectancies of people who have and have not gone to prison, as if “prison” were a disability, they compute that white males lose 19,665 person-years of life to prison per 100,000, black males lose 139,507 person-years, and Hispanic males lose 45,766 person-years.
For comparison purposes, here is a table of person-years of life lost to the most common diseases in the US. Cancer, the top killer, only appears to cost 2882 person-years of life per 100,000. All causes together only cost 38,211 person-years of life per 100,000.
These numbers are really weird. They would place prison as being responsible for nearly half of all person-years of life lost. That would be an utterly shocking result. I’m skeptical.
(ETA: it turns out that the authors of this study were looking at a stock, not a flow, of person-years lost to prison, as Ben notes below. Do not use this study’s numbers to estimate the harms of prison, they don’t make a lot of sense.)
Epidemiologist Ernest Drucker, in his book A Plague of Prisons, tried to quantify the years of life lost to imprisonment for drug offenses in New York State. He estimated a total of 360,000 years of life in prison between 1973 and 2008. This isn’t a fair comparison to diseases, though, because a year living in prison is not as bad as being dead, and prison has harms outside the time actually spent in prison. If we were to count years in prison as “years of life lost”, however, then, given that there are roughly 19 million people in New York, drug offenses alone cost 55 person-years of life per 100,000, which is a more modest number.
A study of the dose-response effect of years of prison on mortality found that each additional year in prison (compared to being released on parole) produced a 2-year decline in life expectancy. For comparison purposes, smokers lose on average 11-12 years of life expectancy compared to nonsmokers. Getting a diagnosis of colon cancer means losing about 10 years of life expectancy, while getting a diagnosis of testicular cancer means losing 1.3 years of life expectancy.
If we combine these numbers, assume each year in prison is roughly equivalent to two years of life lost, then New York State’s drug incarceration is responsible for about 110 person-years of life per 100,000, which is about half the death rate due to HIV. This is a more believable number, though it would still make the list of the top 15 causes of death by years of life lost. But it’s only for drug incarceration, which is responsible for only about 1/5 of all incarceration.
If we look at the total number of people incarcerated in New York State, or 77,227, we get an estimated 810 person-years of life lost to prison in New York per 100,000 population, which is more than the national YLL of homicide. And if we extrapolate to the full 2,220,300 Americans incarcerated, assume 2 years of life lost per year in prison, we get a rate of person-years of life lost due to prison per 100,000 population of 1396, which would make “prison”, if it counted as a cause of death, the sixth worst public health problem in terms of person-years of life lost.
The deadliness of prison, depending on which numbers you use, seems to range from “truly implausibly bad” to “one of the most serious public health problems in America.”
The leading causes of death among former inmates are drug overdose, cardiovascular disease, homicide, and suicide; the highest elevated risks, at 10-12x the population expected rates, were drug overdose and homicide, especially at 0-2 weeks after release. Prison puts people in more danger than they were before.
Some suggested mechanisms for why prison is so dangerous include poor conditions such as overcrowding that expose prisoners to infectious disease; violence within prisons; poor medical care inside prisons; and increased risky behaviors, due to trauma or psychological harm or lack of material opportunities for ex-cons.
For US-centric and present-day-centric utilitarian calculations, prison looks really, really bad. Reducing the prison population seems potentially important on a level comparable to working on Big Problems like cancer, heart disease, diabetes, car accidents, etc.
If nobody were imprisoned for drug crimes, then (aside from any additional risks incurred from the resulting increased drug use) the drop in incarceration alone would save more American lives than eradicating HIV from the US today.
Otium 
I think the figures for life-years-lost-to-disease must be based on some concept of going-to-die-anyway based on life expectancy. To take an absurd example, if everyone dropped dead of spontaneous combustion at exactly age 70, then that would be the life expectancy, and no life-years would be lost to this condition. This underestimates the impact of common diseases. Not exactly apples-to-apples with prison.
As for prison effecting later mortality, how did this address confounders? It won’t be easy to measure them. I only skimmed the study briefly.
On the other side, does this consider people dying in prison? That’s kind of common, isn’t it?
Overall, these quibbles are pretty minor. I think you’re probably right.
There were some controls in the study, but the one thing it can’t adjust for is the fact that people who get paroled earlier were probably better-behaved in prison, which means they’re probably less susceptible to the kinds of things that kill the most ex-cons.
Same for people who have shorter sentences. Among other things, they’re much less likely to be repeat offenders and I’d guess repeat offenders engage in much more risky behavior. I wouldn’t be surprised if this is driving a big portion of the results.
The conclusion strikes me as entirely plausible. Everyone agrees that prison is terrible and you don’t want to go there and being sentenced to life in prison and a steady diet of gangs and rape and poverty is one of the most terrible things that can happen to someone short of actually dying – that’s the whole point of the deterrence paradigm! Prison’s *purpose* is to be awful. It’s not too surprising that on a nation scale, it might be as bad as long-fought diseases.
The real question is what this implies. You can’t get rid of law enforcement or punishing crimes, after all, since whatever the QALY lost to imprisonment, the QALY loss of ‘the war of all against all’ and aboriginal homicide rates of 20% imply the lack would be far worse.
Deterrence is a function of the certainty and swiftness of punishment more than its severity. Extending sentences to long periods and mandatory minimums don’t effectively deter criminals, compared to extensive detection and swift prosecution.
The relevant counterfactual is not “having no laws whatsoever,” it’s “having laws that ban murder but not victimless crimes, etc.”
Which could themselves have bad consequences… Public health considerations of how many QALYs are lost to prison sentences does not justify considering them as a negative because those prison sentences are buying a society with law and order. It is considering costs without reference the benefits. Well, of course anything is going to look bad if you do it like that. (“I took a look at some estimates of taxes. Are you aware that taxes take up literally *trillions* of dollars? Wow! This is absolutely shocking and an economic crisis!” Yeah, I guess taxes *are* pretty big, but I’m not sure how much it can be improved.)
If one wants to argue that it’s a public health crisis, one is going to have to do a *lot* more intellectual work than a simple headcount of prisoners or QALYs in order to establish that the current system is far from optimal in a fixable way and thus the problems are on par with more visible public health problems. (There are, after all, economic arguments that there isn’t nearly enough law enforcement & prison given the large negative externalities and social costs of crime. Bryan Caplan’s blogged a few papers like that.)
It’s weird that people are thinking I mean that prisons have no benefits and only costs, just because I’m only *looking* at costs in this one blog post. I compare things to diseases to get an idea of *magnitude* — like, how much could improving criminal justice buy, if it were done optimally?
Also, if you think about the ways in which prison is awful in real life, saying ‘it’s supposed to be that way’ makes you sound like a cartoon villain, and I am comfortable not taking seriously any morality where “yep, rape sounds like a good punishment” is a statement that people make in earnest.
You wrote a post comparing prison to a disease. Diseases almost never have any benefit and are pure cost. Don’t blame me for your poorly chosen analogy. Also, it’s bizarre to make comparisons to cartoon supervillains when the overwhelming majority of the population endorses retributive & deterrence and has no problem with prison rape, which is a big part of why it all exists in the first place.
I’m sorry, yes. Misunderstandings are learning opportunities for the writer.
I’m afraid I just don’t understand what the majority of the population’s opinions have to do with what’s true.
You don’t see what’s wrong with comparing a majority opinion to ‘cartoon supervillains’? That’s super-bubblicious.
what can I say, I just have a charmingly bubbly personality.
Very good points, just keep in mind that many prisoners (especially the 40% in there for violent crimes) they may be safer inside prison than outside prison… living in impoverished areas also takes years off your life and most of these people live in poor areas.
After reading the methodology, I’m pretty confused about what that first study (Hogg et al) was doing. I couldn’t really follow it so I might just be confused but I don’t think they actually had any data on life expectancy of people who have been incarcerated that they could have used to compare to others’.
Is it possible that what they did is just count every year in prison as a year of life lost?
Relatedly I’m pretty confused by why this would work:
“Person-years of life lost to imprisonment were calculated by multiplying the number of persons imprisoned in a specific age group by years left to 45 years. Person years were then totaled for each gender and racial group and expressed as person years lost per 100,000 population.”
Do the studies isolate the causal effect of prison time on lifespan? I’d guess that there is also a large selection effect. e.g., Drug users are more likely than non-users to die prematurely of overdose, and drug users are more likely than non-users to spend time in prison, so people who’ve spent time in prison are more likely to die prematurely of overdose.
The one study that found a dose-response effect of prison on lifespan, depending on when people were released for parole, seems to at least partially avoid this problem.
Aren’t parole decisions based largely on predictions of future criminal activity? I’d expect future criminal activity to correlate with mortality rate. I also expect that many of the variables that are used to predict future criminal activity to independently predict mortality rate. For example, the Post Conviction Risk Assessment predicts recidivism risk based on criminal history, education/employment, substance abuse, social networks, and cognitions.
ooh I did not not know that existed, thanks!
>Comparing life expectancies of people who have and have not gone to prison, as if “prison” were a disability, they compute that white males lose 19,665 person-years of life to prison per 100,000, black males lose 139,507 person-years, and Hispanic males lose 45,766 person-years.
>For comparison purposes, here is a table of person-years of life lost to the most common diseases in the US. Cancer, the top killer, only appears to cost 2882 person-years of life per 100,000. All causes together only cost 38,211 person-years of life per 100,000.
The prison YLL estimates were pretty hard to interpret, but I think the reason the numbers are so big is because it’s in different units than the NIH disease mortality numbers. From the paper you linked:
>To provide context, rates of imprisonment and person-years of life lost to imprisonment were first calculated. Rates were calculated for each year, 2000 through 2004, for the age group 18 to 44 years. Rates of imprisonment in this age group were the average of the number of persons in prison per 100,000 population. Person-years of life lost to imprisonment were calculated by multiplying the number of persons imprisoned in a specific age group by years left to 45 years. Person years were then totaled for each gender and racial group and expressed as person years lost per 100,000 population.
As far as I can tell, here’s what they did. They assumed that everyone in prison is released at the age of 45. (This seems like a weird assumption but maybe it gives you numbers close to the true ones?) So they limited their analysis to people age 18-44. For each calendar year reported, they counted the total number of people in prison in each group, and divided this by 100,000, to get the “Rate of imprisonment.” Then, to calculate “Person-years of life lost to Prison”, they multiplied this by the difference between the average inmate’s age and 45. Another way of putting this is that they summed the difference between each inmate’s age and 45, and divided by 100,000. (I backed out the multipliers and they’re all in the range 10-15, implying average ages in the range 30-35, about what you’d expect.)
This means that there’s substantial carry-over from year to year. For instance, the paper reports 141,108 African American “Person-years of life lost to Prison” per 100,000 people in 2000, out of 9,885 incarcerated per 100,000. The way they calculated it, if no one were imprisoned after 2000, the number reported in 2001 would be 141,108 – 9,885 = 131,223. In 2002 it would be 121,338, and so on.
By contrast, the NIH table is counting years of life lost due to disease-related deaths each year:
>Person-Years of Life Lost is measured as the difference between the actual age stemming from the disease/cause and the expected age of death due to a particular disease or cause. Specifically, this measure is estimated by linking life table data to each death of a person of a given age and sex. The life table permits a determination of the number of additional years an average person of that age, race, and sex would have been expected to live.
These don’t carry over. Each year, a certain number of people die from a disease. For each person who dies, the NIH calculates the difference between the person’s age, and the life expectancy at birth of someone with their demographic characteristics. This is their estimate of that person’s years of life lost due to their cause of death. They then sum these estimates, and divide by 100,000. So, if I have terminal cancer this year, and die next year, this year I have 0 years of life lost, but next year my cancer is responsible for lost decades. This is an imperfect measure but at least measures a rate of some kind.
Comparing these two rates is comparing a stock and a flow. To get the “flow” numbers for years lost to prison, you would want to count total expected years incarcerated for people newly imprisoned each year. You can do this by taking “Person-years of life lost to Prison” in one year, and subtracting the number you’d expect if there were no new incarcerations (i.e. the reported “Person-years of life lost to Prison” for the previous year, less the reported “Rate of imprisonment” to account for each existing prisoner being a year closer to getting out.) For example, in 2001, the reported “Person-years of life lost to Prison” for African American men is 141,602. As calculated above, the expected number with no new incarcerations is 131,223. Therefore, new incarcerations between the 2000 and 2001 reporting dates account for 10,379 “Person-years of life lost to Prison” per 100,000 African American men. This is only half an order of magnitude more than cancer – by this estimate the average African American man spends 3x as many years in prison, as the average American’s lifespan is shortened by cancer. A bit of an odd comparison, but at least we’re not mixing stocks and flows.
Note that this backing-out method doesn’t give very accurate estimates. Some year the number is negative, presumably because the rule “prisoners are released at age 45” isn’t a perfect fit for the data, and some years many more people were released than that model expected, driving down the estimate of # of years left.
Correction:
>For instance, the paper reports 141,108 African American “Person-years of life lost to Prison” per 100,000 people in 2000, out of 9,885 incarcerated per 100,000.
The number is specifically for African American men.
I put together a spreadsheet with the calculations referenced in my comment: https://docs.google.com/spreadsheets/d/1XemNtJpjMJkqPdIcriJBO1eXwFKQaSKOLYwPDLEN3pU/
I’m probably just not following but is it possible their calculation is assuming nobody incarcerated in a given year gets out before the age of 45? Hard to follow their calculations on BART. But it feels like that’s the effect of taking the difference from 45 and multiplying out.
I think that is in fact what they’re assuming in the calculation: no one is released until age 45, at which point they’re released with certainty.
“Person-years of life lost to imprisonment were calculated by multiplying the number of persons imprisoned in a specific age group by years left to 45 years.”
Small note: I’d recommend you add “In the United States” to your first sentence (“As of 2013, 2,220,300 adults were incarcerated in state and federal prisons and county jails.). I think that would make it clearer and less implicitly US-centric.
Thanks!
“a year living in prison is not as bad as being dead”
After working in a jail (albeit as a therapist, so selecting for the unhappiest prisoners), that’s not my intuition at all. A lot of people try to sleep away as much of their sentence as possible. I bet if you offered inmates the chance to spend the rest of their sentence in a coma and wake up at the end having not experienced it at all, most of them would say yes.