An Enforced Death Penalty Saves Lives Through Deterrence
There has been a sea change in the scholarly literature on deterrence in recent
years. Dr. Paul Rubin of Emory University summarized it in his
congressional testimony in 2006. "The literature is easy to summarize:
almost all modern studies and all the refereed studies find a
significant deterrent effect of capital punishment. Only one study
questions these results."
Opponents frequently
make the claim that the lower homicide rates in states that do not have
capital punishment disprove deterrence. This argument is so obviously
invalid that a sophomore social science student could see it. Such
simplistic comparisons fail to control for the other ways in which the
states vary. We don't have to guess about this; we know. Those same
states had lower rates during the moratorium period of the late 1960s
to mid 1970s when no executions occurred in the United States.
The
studies that properly control for the other variables are the ones
referred to in Dr. Rubin's testimony. Although it is not an exact
science, and probably never will be, a remarkable number of researchers
using different approaches have produced a strong consensus that there
is a deterrent effect where the death penalty is genuinely enforced.
Estimates vary, but it is likely that somewhere in the range of 5 to 18
innocent lives are saved per execution.
What
happens in states where the death penalty is obstructed, such as
California and Pennsylvania, is insufficiently researched to draw any
firm conclusions, but in any event the correct policy response is to
remove the obstruction.
Faced
with the modern deterrence studies, opponents usually cite the critical
article by Donohue and Wolfers. Unlike the authors of the studies
finding deterrence, Donohue and Wolfers chose not to publish their
article through the peer-reviewed publication process that is the
standard in the field for assuring that research meets at least the
basic criteria for validity. Instead, they chose to publish in a law
review. Law reviews are edited by law students who typically do not have the education
or experience to distinguish valid social science methodology from
statistical sleight-of-hand. Why did Donohue and Wolfers bypass the
standard review process? Applying the Harry Truman principle, if you
see someone avoiding the kitchen, there is a good chance he can't take
the heat. Dezhbakhsh and Rubin's response to Donohue and Wolfers is
presently in the "working paper" stage and is available on SSRN , abstract 1018533.
It
is a basic principle of human behavior that incentives matter. Increase
the cost of doing anything, and fewer people do it. When the price of
gas goes up, more people take the bus rather than drive. Applying that
basic principle, we would expect that a credible, enforced death
penalty would reduce the number of homicides, particularly the
premeditated homicides that are generally punished by death. (Whether
second-degree murder or voluntary manslaughter would be deterred is
moot, as these crimes are not capital, and there is no serious proposal
they should be.) Those who would claim that murder is somehow
different, an exception to this basic principle, would need powerful
empirical evidence to support that claim. The evidence is powerful in
the other direction.
Using the Emory study estimate, over 18,000 have been saved from murder by the enforcement of capital punishment from 1977 to 2006. Tens of thousands more could have been saved if enforcement had not been obstructed by excessive delay and by overturning judgments based on fabricated restrictions that are not really in the Constitution and have nothing to do with actual guilt of the crime.

The only compelling reason I've ever heard for the death penalty is that it gives the families of the victim(s) closure. However, that is not the government's responsibility. Its responsibility is to prevent the murderer from having the ability to murder again. And in the unlikely event that new evidence overturns a conviction, a person can be let out of prison, but the same person cannot be made undead.
Is the death penalty a deterrent? I think it's negligible and probably impossible to prove. It's unlikely that anyone committing a murder does so because they think they'll only get life in prison.
Among the innumerable,screwed up, neo-con principles that seperates Americans and divides this nation, the death penalty is a core tenet........an eye for an eye, assuage your grief (fear,loathing,anger, superiority, etc.) by punishing the offender and if a few mistakes are made, too bad.
In most civilized societies, the idea of killing the killer is contradictory, ignorant and clearly ineffective. If the crime is pre-meditated, the last thing going through the criminals mind is being caught and facing a death penalty. If the crime is one of spontaneous rage, the fear of apprehension or subsequent death is totally absent, at least until the offender returns to a calmer state. If the crime is a toxic blend of addiction and insane pleasure(serial killers) getting caught and being executed are, more or less minor irritations, if not welcome relief. If the crime is a "professional hit" or something similar then there is little fear of the consequences and a surity of being able to evade them easily. If the crime is accidental, there is no death penalty, unless it occurs in the committing of another crime ( robbery , rape , etc.) and so on.
Those who quote spurious and highly politically spun "statistics, research and proofs" that the death penalty is an effective deterrent are in the same class as those who claim their particular religious dogmas, books, beliefs, words of Divine guidance, ad nausea are deluded and morally simplistic.
Every religious text has, among other Values, the basic tenet that the sanctity of life is unbreachable and that no one has God's authorization to take life, period. Despite this, the fanatical religious right, along with the fanatical terrorist minorities and the dissolute, corrupt dictators worldwide perversly adhere to their "right"to kill whomever they determine to be enemies of God, the State, criminals or even their personal adversaries.
I am a proud citizen of a nation who has ended capital punishment decades past and it is one of the safest, least violent countries in the world. We also strictly control access to weapons by the general public AND employ an effective, carefully monitored supervision and training for those given the priviledge to own a weapon. Our violent crime rate has declined over the past 40 years by about .8% per year while about 5% of those imprisoned for a capital crime have subsequently been released as innocent of their original "crime". It is singularly hypocritical to maintain that the most just and rightful punishment for murder is to murder the offender, but the gut satisfying appeal of watching the person who murdered being subjected to the same treatment as their victim(s) is a particularly difficult addiction to break.
The mind of a person who commits a murder can only be in a limited number of states at the time of the crime . 1. They do not believe they will be caught. 2. They are in such a rage that they don't care if they are caught. 3. They are unaware of the seriousness of the crime or they don't believe what they are doing is wrong. (Usually insanity or mental retardation is a factor) 4.In rare cases, they want to be caught.
In any of those cases the death penalty has no detterent effect, whatsoever.
I have had reason to go to prisons in connection with my former work. I can tell you that the death penalty is more welcome for a perpetrator than life without parole. Life places him in the population where his life is worth nothing. The death penalty is not and has never been a deterrent for the criminal. If he thinks about it at all he does not feel he will be caught.
I don't suppose it cuts any ice with you that the rest of the world sees this as pre-historic? I also don't suppose it matters that those countries that don't have the death penalty don't have as many murders as the USA? Your logic is flawed and outdated. The death penalty is a sign of a society that is backward. You're in bed with China and all the other backward countries in the world. Shame. Why don't we start burning witches again too?
Your last sentence requires that the system change since what you propose restricts (generally) due process and thus is unconstitutional. This may be a desired change but it is one that actually weakens your death penalty argument since these restrictions make it more likely that the guilty are proven as such and the innocent are not. If you concede that death is irreversible then any change that increases likelihood of "false proof" is incompatible as an argument supporting the death penalty.
Assuming that using an imperfect system for deterrence at the risk of harm to innocent persons is unacceptable; regardless of its deterrence effects the system must stand on its own first. Given the maximum harm possible by the system (death) what is the maximum level of risk/accuracy we are willing to accept (false positive percentage). If our courts can be shown to meet that level of accuracy then the system should be deemed acceptable otherwise it should be canned. What level of accuracy would you impose on a system for which an inaccurate result ends in death? How accurate is our current system? What is the cost associated with this and other levels of accuracy?