A crazy, mad science idea : proving if the death penalty is effective

In My Humble Opinion
1

So I was thinking about how if you want to prove if 2 variables are connected (say death penalty punishment and murder rate), you need to see in the data a clear correlation that is causation.

Let me give a stock market example. Suppose you notice that the price of bananas and the price of big macs are correlated. As big macs go up in price, so do bananas.

To show causation, you might see if there is a predictable phase lag between a change in big mac price (say 3 months) and a change in banana price. If every time the big mac changed in price, the banana changed in price 3 months later, and no changes in banana prices happened when the big mac price was constant, you have fairly solid evidence of causation. The more times this has happened in your data, the stronger the probability that big mac prices predict banana prices to change is. (and some underlying mechanism of causation is involved)

Well, some people argue that the death penalty decreases homicides. It would be straightforward to prove or disprove this. It’s simple - toggle the death penalty on and off like a step function, at different frequencies, and see if the murder rate goes up and down at the same frequency following a phase lag.

So for a 5 year period, anyone caught for murder in that state (better to do it nationwide but you know) will be executed. The next 5 years, they get life in prison. Do this 1-2 cycles. Then make the period 2.5 years, and same thing.

This would create clear proof one way or another, as if the hypothesis that “executions reduce homicides significantly” is correct, stopping and starting executions should cause a clear trend in the data. There should be a significant increase in murders during the 5 year “only life in a cage” period, and a decrease during the “to death row you go” period. And the period of increase and the period of decrease should be 5 years long. And 2.5 years for the second cycle.

Is there a formalized mathematical way to actually prove, based on the number of cycles you conducted the experiment and the relative effect - how *certain *you are of your conclusion?

Back to the banana example : if you used automated software to discover this relationship between big macs and bananas, you could make a nice profit trading banana futures. But you need to calculate the probability based on N observed correlated big mac->banana events, and M relative price swings in banana prices, and O uncorrelated banana price swings how likely it is your model is correct. That way you know whether you should bet real money on this.

2

One needn’t plan future experiments; one can study the past — homicide rates in states before and after they abolished the death penalty, or comparing similar states. Many Google hits on such studies include this summary by a Math Professor. It seems capital punishment is, on balance, not a deterrent. It may discourage some murders … but encourage others!

3

There’s also a very clear relationship between executions and copycat crimes of the executed person on the day and night of the execution. Those go way up.

4

In order to get scientific valid results, there would need to be a control group of innocent people who are selected at random off the streets, and executed. Any scientific study of the effects of killing human beings runs into certain societal problems with methodology.

Another problem arises with the metrics. Exactly what observable outcome is expected from executions, and how is that outcome measured? There seem to be different schools of thought on what the public expects to gain from executions.

5

Long periods of incarceration for heinous crimes are cruel, and expensive as hell for the taxpayer. The DP is a good compromise for everyone.

6

Except it’s even more expensive than life imprisonment.

7

Well, as a control, you could announce an execution without doing one.

But personally, I think the control isn’t executed innocents: it’s non-executed guilty, which was in the OP’s proposal.

But truthfully, many people’s real motive is revenge. The dress it up as deterrence to try to make it more tolerable for the antis, but we know it doesn’t work.

8

I know, that’s fucking stupid ain’t it?

9

I’d like to see the math on that. It seems to me that shooting/hanging/electrocuting a, say 35 year old is cheaper than feeding and sheltering him for 40 years.

May I request you use Charles Manson for your example to demonstrate how much money the American tax payer has saved?

10

Well, not locking them up at all would be even cheaper, but you do want a criminal justice system run by economics?

11

For crying out loud, pickpockets worked the crowds at public executions when the ones being hanged were pickpockets. Some deterrent.

12

Given the significant number of people executed for whom evidence has later been found to be fraudulent, confessions coerced, and eyewitness testimony recanted, not to mention widespread fraud and malfeasence in forensics labs and numerous cases of prosecutorial misconduct in suppressing exculpatory evidence and testimony, the legal precautions granting substantial latitude for appeals is well justified. Once executed, we cannot provide any useful clemency for a false conviction. I don’t have any problem with the perpetrators of violent crimes ending up in the morgue, but an objective review of the history of the use of the death penalty in the United States certainly gives reason for skepticism that our legal system is reliable enough to make those kinds of decisions without substantial potential for wrongful execution.

Most states require automatic appeals in convictions resulting in a death penalty result. Even if the defendant does not wish to pursue an appeal, the automatic appeals process alone can take several years as appeals courts are often overloaded and understaffed. In the case of a vigorous defense there is often credible reasons to challenge a conviction on evidential, procedural, or technical grounds, and in order to minimize the potential for a gross miscarriage of justice resulting in the execution of a person who was convicted based upon bad evidence, false testimony, or cultural bias every credible exception should be addressed by the appeals process.

Citing Charles Manson, the schizophrenic leader of the so-called “Manson Family”, as evidence of the need for capital punishment is a non-sequitur. Manson was never convicted of murder, nor was there evidence that he directly committed any murders or other capital crimes. He was convicted of conspiracy to commit murder in 1971, over a year before California suspended executions due to the decision in People v. Anderson in April 1972. Conspiracy is not a crime for which the capital penalty can apply, and it would be almost trivial for a competent judge to demonstrate that Manson, who clearly suffers from severe mental illness, is not competent sufficient to justify a capital conviction. Manson, a multiple convict who had spent half of his life prior to the 1971 conviction in prison, is actually evidence that we need a more robust mental health diagnostic and recidivism abatement process to address career criminals and people with dangerously severe psychoses.

Stranger

13

except predictors are not necessarily causers. You"re still not proving causation, only that the two are linked. There may be an external cause that effects both big macs and bananas, but it takes 3 months longer for the effect on bananas to reach the market. To prove causation you have to show how the underlying mechanism works.

mc

14

I wasn’t attempting to challenge or debate what crime Manson was convicted of nor the legal justification for it. I just see him as a good example for a financial analysis, since he has been incarcerated for life after having his death penalty overturned. The non sequitur is bringing his crimes into the equation.

I agree strongly with everything you wrote about wrongful executions and especially the part of your statement that I bolded, but it too is irrelevant to an economic analysis.

I’m truly interested in the economic argument.

I probably sound trollish here, and I apologize if that is the case - I’m not trying to be. Economics above all else is my basis of support for the death penalty in principle, and if I were to have it demonstrated to me that it is truly cheaper to incarcerate these people for life, I would have to revise my opinion.

15

In recent decades, the word “revenge” has been replaced by “closure”, which is tantamount to the same thing, but is a more touchy-feely euphemism.

16

Stranger, Marlonius : rather than rehash tired pro/anti death penalty arguments, how about evaluating my experimental design? I mean, wouldn’t it be nice to shine the bright light of truth and actually find out, one way or the other, what effect the death penalty has?

If it’s the same state, and 5 year periods of time, then you’re controlling for almost every other variable by doing : death penalty, no death penalty, death penalty, no death penalty. If people commit less homicides during the no death penalty periods, you have evidence that it has a deterrent effect. Once you know how much the difference is - is it 10%? 50%? 200%? - you can reasonably work out the cost to society of each murder versus the (cost to execute / deterrent effect) and rationally make your choice based on data and evidence, not kneejerk opinions.

Surely you both agree that knowing is better than not. The problem with “naturally” occurring experiments like that one brief death penalty ban in the past is that it only happened once, and the demographics of America changed, leaded gasoline was banned, abortions were made legal, and so on, and for whatever reason, there has been a large and steady drop in crime up to the present day.

17

something similar has been done.

but, again, this doesnt show causation, only correlation.
mc

18

I mean you must have only the most casual, drive by interest in this. Seriously, man, have you not once googled this, just once, in all the time you’ve been saying “Economics above all else is my basis of support for the death penalty”.

In every state in the United States that performs executions, in the real world, the cost of the appeals makes capital punishment significantly more expensive(3). There’s not a legal to stand on regarding economics.

As Stranger on The train points out, 144 people on death row have been exonerated so far(1). That is, found to be innocent of the crime they were given a death sentence for, by a court of law that allegedly was unbiased and needed evidence beyond a reasonable doubt.

Most death penalties are never carried out and the most likely outcome for an inmate on death row is for their case to be overturned on appeal(2). (for most of these individuals, they were not found innocent, just the State decided that killing them was not warranted)

So you cannot reasonably argue that the appeals process should be shortened or made cheaper. If it were, thousands more people would have been executed, and at least 144 of them were completely innocent.

(1)One in 25 Sentenced to Death in the U.S. Is Innocent, Study Claims - Newsweek
(2) https://www.washingtonpost.com/news/monkey-cage/wp/2015/03/17/most-death-penalty-sentences-are-overturned-heres-why-that-matters/?utm_term=.94a04796e318
(3) http://www.nytimes.com/2009/09/28/opinion/28mon3.html , there are a dozen other sources that cover different aspects of this.

19

The relative cost of life imprisonment and execution is mainly a function of the required added certainty of fair process* the public demands in one case v the other. I’m practically against the DP (also don’t like it morally but the practicalities decide it) based on the reality of society’s demand for certainty. I don’t know how you determine when that crosses the line of ‘stupid’. But the DP is impractical in US society as it now exists, and it’s IMO only a matter of time till it’s abolished.

Like other DP discussions there’s also the implicit and completely unrealistic assumption that ‘killers get executed’, anywhere. In TX IIRC low single digit % of people convicted of all forms of unlawful killing are executed. So how is executing X small % of killers much of a deterrent at large? The answer IMO comes more into the realm of easy common sense, it’s obviously not much of one, even if stats could be tortured to say it is so slightly.

*which is easier to prove falls measurably short of 100% than finding cases of factually innocent people executed in recent time. But that feeds back to the fact that the prolonged expensive process uncovers cases where the factually innocent would have been executed in numbers in a very ‘streamlined’ process.

20

From an experimental standpoint, the notion of being able to control variables so that a clear correlation between the implementation of capital punishment and the efficacy of it in terms of deterrence is pretty much impossible. For one, there are relatively few crimes committed that warrant capital punishment, and the definition of those that do tends to fluctuate wildly depending on the degree of public outrage of the crime fueled by media coverage or lack thereof, the enthusiasm of the prosecutorial office in pursing politically valuable but costly capital punishment cases to judgement rather than pleading out for life sentences, the socioeconomic status of the defendant and often that of the victims, the whims of a jury drawn from people who largely couldn’t figure out a way to escape jury duty and who often have little understanding of the niceties of the law, and the judge’s instructions on sentencing which may constrain how a jury can justify their decision. When you are only getting a handful of cases a year at most that go all the way to jury decision to apply capital punishment in differing crimes and circumstances it is going to be very difficult to show any credible correlation, especially since the certainty of the application of capital punishment has to make its way through the subculture of people who may commit capital crimes, so there will be a lag until consistent executions are the default result of being convicted of a severe crime.

And frankly, there is little evidence that incarceration or execution has any real impact upon serious crime. Harsh penalties and public humiliation are effective in the case of more modest property crimes by normally law abiding people specifically because they are or want to be part of society. Habitual violent criminals know that they are not a part of society at large, and most even view normal social roles and careers and the people who live them with disdain; as a class of people, they’ve learned to survive by manipulating others, and genuine sociopaths aren’t even inclined to the kind of empathy necessary to adhere to the social compact. One can argue about the efficacy of various methods of rehabilitation (although our justice system does not practice convict rehabilitation in any consistent, overarching form, so there is little that can be definitively said about that) but the threat of long term incarceration or execution would appear to have almost no effect on ordinary violent crime, as can be seen by the “War on Drugs” which has served only to create an industry of privitized prisons but do nothing to stop illegal drug distribution and associated violence.

So no, I don’t think it is practical to show or falsify correlation (much less causation) between crime rates and capital punishment by the simple method outlined by the o.p. to any degree that would be regarded as statistically significant even at the 50% confidence level. The general evidence about crime rates and imprisonment, while perhaps not directly applicable to punishment resulting in the termination of life of the offender, would seem to indicate that punishment has little effect on violent crime rates despite continued harshening of the consequences, and there is really no reason to expect this to be different with capital crimes.

Stranger