<p>The literature on this issue flip flops. The first seminal study by Sellin (1959)¹ did not find any significant effect, but early literature was riddled with methodological errors. Ehrlich’s (1975)² study at the time was far more sophisticated, and it showed a strong deterrent effect of capital punishment. However, ironically, this study later too became criticized for lack of empirical rigor (as the statistical method advanced). Cochran and
Chamlin (2000)³ and Lamperti (2008)⁴ showed that not only it did not deter violent crimes, but it could also have even increased them via the 'brutalization' effect. However, later Dezhbakhsh,
Rubin, and Shepherd (2003)⁵ employing panel data again showed it has a deterrence effect, but that study was later itself challenged by Kovandzic, Vieraitis, and Boots (2009)⁶.</p>
<p>New meta analyses show that evidence is somewhat mixed too. For example, meta analysis of Yang &amp; Lester (2008)⁷ argues there is a significant deterrence on some crimes, but meta analysis of  Dölling et al. (2009)⁸ finds that the effect of capital punishment on violent offenses is not significant. It is very hard to fish out the true effect because of endogeneity issues. Places in US with high violent rates often have capital punishment, is that because those places need the deterrent most or because it is ineffective deterrent and other places have better policies? Although it is matter of ongoing discussion most researchers now tend to lean more to the side that capital punishment is not effective deterrent but the research is not fully settled.</p>
<p><strong>References</strong></p>
<ol>
<li>Sellin, Thorsten. 1959. The death penalty. Philadelphia, PA: American Law Institute.</li>
<li>Ehrlich, Isaac. 1975. The deterrent effect of capital punishment: A question of life and death.
American Economic Review, 65: 397–417.</li>
<li>Cochran, John K. and Mitchell B. Chamlin. 2000. Deterrence and brutalization: The dual effects of executions. Justice Quarterly, 17: 685–706</li>
<li>Lamperti, John. 2008. Does capital punishment deter murder? A brief look at the evidence.
Retrieved October 8, 2009 from math.dartmouth.edu/~lamperti/capitalpunishment.pdf</li>
<li>Dezhbakhsh, Hashem, Paul H. Rubin, and Joanna M. Shepherd. 2003. Does capital punishment have a deterrent effect? New evidence from postmoratorium panel data.
American Law and Economics Review, 5: 344–376</li>
<li>Kovandzic, T. V., Vieraitis, L. M., &amp; Boots, D. P. (2009). Does the death penalty save lives? New evidence from state panel data, 1977 to 2006. Criminology &amp; Public Policy, 8(4), 803-843</li>
<li>Yang, B., &amp; Lester, D. (2008). The deterrent effect of executions: A meta-analysis thirty years after Ehrlich. Journal of Criminal Justice, 36(5), 453-460.</li>
<li>Dölling, D., Entorf, H., Hermann, D., &amp; Rupp, T. (2009). Is deterrence effective? Results of a meta-analysis of punishment. European Journal on Criminal Policy and Research, 15(1), 201-224.</li>
</ol>

CC BY-SA 4.0
2021-07-11T11:07:43.980Z
Interesting bit about the correlation between high crime prevalence and harsh laws. A conjecture coming to my mind is that such communities focus on the wrong things, namely ineffectual punishment instead of "soft" interventions that strengthen the social fabric and provide alternatives to a criminal career for young men. The Freaconomics drug dealer chapter anecdotally shows how being a low-earning, high-risk criminal is a rational decision when no other opportunities exist. The dealers directly risk their lives -- their death rate is higher than on death row -- but that does not deter them.
Peter - Reinstate Monica
CC BY-SA 4.0
2021-07-12T04:02:40.003Z
All these studies seem focused on the USA. I'm curious if there are any studies related to the execution of drug smugglers & the low crime rate in Singapore.
Astor Florida
CC BY-SA 4.0
2021-07-12T13:41:36.220Z
@axsvl77 If you look at international comparisions here you should also notice that every single European country does not have the death penalty and every single one of them has a much lower murder rate than the US. Singapore also has lower crime rates than the US and has the death penalty.
quarague
CC BY-SA 4.0
2021-07-12T13:49:32.853Z
@quarague So are you saying there may be times when the death penalty does not work, and that there may be times when it does? I agree. OP asks "when and why does capital punishment work ". I think that your comment is the first look at actually answering this question.
Astor Florida
CC BY-SA 4.0
2021-07-12T14:30:15.800Z
@axsvl77 It seemed like you wanted to argue that the death penalty works by citing the example of Singapore. I think this would be a highly selective view as there are plenty of other countries with low crime rates without the death penalty. So it is not death penalty may or may not work but rather low crime rate can be achieved with or without death penalty.
quarague
CC BY-SA 4.0
2021-07-12T16:02:03.437Z
@quarague History is complicated. I don't want to speculate about what studies related to Singapore's prolific executions might show. I just do know that this answer, despite the upvotes, does not answer the question because it is focused on only the USA. I was, and am suggesting that this answer should be expanded to include more information.
Astor Florida
CC BY-SA 4.0
2021-07-13T06:03:29.530Z
@axsvl77 Singapore is also a police state, and a very small single city that is easy to police. The risk of getting caught is extremely high (at the expense of a huge loss of privacy for the citizens). The low crime rate there may be more due to the near-certainty of getting caught than due to harsh punishments.
Kevin Keane
CC BY-SA 4.0
2021-07-13T13:03:09.913Z
@KevinKeane OP asks "when and why does capital punishment work ".  So find sources for your comment, and make it an answer, and I will upvote you.
Astor Florida
CC BY-SA 4.0
2021-07-16T10:56:32.463Z
@axsvl77 if you are interested about Singapore maybe try asking a separate question about it. I focused on US because that is where most research on this was done. I wanted to focus on main literature in this answer, work on Singapore is quite niche, I can't even think about a widely known paper just from top of my head but for sure there must be some.
WilliamT
CC BY-SA 4.0
2021-07-10T11:26:12.980Z
2021-07-12T14:23:12.150Z
2021-07-12T14:23:12.150Z
WilliamT
<p>The death penalty as a deterrent to crime is ineffective is the prevailing view amongst researchers and experts in the field of criminology.
Some studies would indicate that there is no correlation between the death penalty and the reduction of violent crime. However, like any topic, you can find contrarian views that say there is no conclusive evidence to say that it does not. The increased use of econometric models is inconclusive aswell.</p>
<p>&quot;The data alone cannot reveal what the homicide rate in a state without (with) a capital punishment regime would have been had the state (not) had such a regime.&quot;</p>
<p>&quot;In their book, Professors Hood and Hoyle say almost all the academic studies available for review are concerned with the deterrent effect of capital punishment on the rate of murder in the United States.</p>
<p>The authors say theoretical and methodological issues have 'dogged the attempts to prove or disprove the existence of the deterrent effect of executions in the United States' and 'a fierce controversy continues' in the United States over attempts to use econometric models to address the question.</p>
<p>After reviewing the literature they conclude that 'it is not prudent to accept the hypothesis that capital punishment, as practised in the United States, deters murder to a marginally greater extent than does the threat and application of the supposedly lesser punishment of life imprisonment'.&quot;</p>
<p>&quot;His position is shared by the majority of criminologists in relation to homicide, according to a 2009 survey of members of the American Criminology Society, who were asked to limit their answers to their understanding of the empirical research and to exclude their personal opinions. That study found that over 88 per cent of the criminologists did not believe the death penalty deterred murderers.&quot;</p>
<p>&quot;A comprehensive review of the research in this area over 34 years was conducted in 2012 by a committee of the American National Academy of Sciences National Review Council. The committee concluded that &quot;research to date on the effect of capital punishment on homicide is not informative about whether capital punishment decreases, increases, or has no effect on homicide rates&quot;</p>
<ul>
<li><a href="https://www.abc.net.au/news/2015-02-26/fact-check3a-does-the-death-penalty-deter3f/6116030?nw=0" rel="noreferrer">https://www.abc.net.au/news/2015-02-26/fact-check3a-does-the-death-penalty-deter3f/6116030?nw=0</a></li>
</ul>
<p>Furthermore, as a penalty itself, the death penalty is morally repugnant and an anti-thesis to any government that would claim moral authority over its citizens.</p>
<p>Additionally, it is extremely costly as a form of punishment, some within the UN argue it can constitute torture and for its finality as a punishment, there is far too much human error involved in its delivery.</p>
<p>&quot;From 1973 through December 2014, 150 innocent people were exonerated from death row&quot;- <a href="https://www.aclu.org/issues/human-rights/human-rights-and-death-penalty" rel="noreferrer">https://www.aclu.org/issues/human-rights/human-rights-and-death-penalty</a></p>
<p>Then there are the issues within the legal institutions that would apply it, and the biases they hold.</p>
<p>• Jurors in Washington state are three times more likely to recommend a death sentence for a black
defendant than for a white defendant in a similar case. (Prof. K. Beckett, Univ. of Washington, 2014).
• In Louisiana, the odds of a death sentence were 97% higher for those whose victim was white than for those whose victim was black. (Pierce &amp; Radelet, Louisiana Law Review, 2011).
• A study in California found that those convicted of killing whites were more than 3 times as likely to be sentenced to death as those convicted of killing blacks and more than 4 times more likely as those
convicted of killing Latinos. (Pierce &amp; Radelet, Santa Clara Law Review, 2005).</p>
<p>In terms of economic analysis, I don't know if this is what you had in mind, but it is related, with cited research by economists who've endeavored to study the issue through that lens. Albeit from 1996</p>
<p><a href="https://digitalcommons.iwu.edu/cgi/viewcontent.cgi?article=1001&amp;context=uauje#:%7E:text=The%20marginal%20economic%20cost%20of,to%20put%20somebody%20to%20death" rel="noreferrer">https://digitalcommons.iwu.edu/cgi/viewcontent.cgi?article=1001&amp;context=uauje#:~:text=The%20marginal%20economic%20cost%20of,to%20put%20somebody%20to%20death</a>.</p>
<p>A small snippet from the above link - &quot;In 1973, economist Isaac Ehrlich studied data from robberies that occurred in the 1940s,1950s, and 1960s. He found that the higher the probability of conviction for robbery, the
lower the robbery rate, ceteris paribus (Cooter and Ulen 1988). However, he found that the severity of the punishment did not affect deterrence in 1940 and 1960. Interestingly, he found a deterrent effect based on the severity of punishment when studying robbery reports from 1950. More recently the Capital Punishment Research Project and the New York Times compared capital and non-capital states to assess deterrence effects (Economist 1994a).The investigation examined the number of murders that occurred in New Jersey before and after the imposition of a death penalty statute in 1982. No statistically significant decrease was found in the number of murders that occurred. The study also compared the number of murders per 100,000 residents in both Massachusetts (a non-capital state) and New Jersey (presently a capital state). No significant difference was found in the number of murders. In the same study, the murder rate in New York (a non-capital state when the study was conducted) was compared to the rate in Texas (a capital state); and there was no statistical difference between the two states with respect to the number of murders per 100,000 residents. Interestingly, while most southern states have the death penalty, they also have higher murder rates. In fact, Louisiana, a capital state, has the highest murder rate in the nation. Among southern states, only Florida has a murder rate below the national average&quot;</p>
<p>In terms of overall views on the subject, it differs highly in which country you are referring to, as it is not just a scientific issue, but a political one. There is also unfortunately a lot of ignorance and emotionally distorted reasoning when dealing with the topic with those unfamiliar with it.</p>

CC BY-SA 4.0
2021-07-10T10:46:03.420Z
this answer just argues against the use of death penalty instead of answering the request for empirical literature review on its efficacy
WilliamT
CC BY-SA 4.0
2021-07-10T12:02:42.547Z
Your answer has valuable information, it could be pruned a bit to make it more focused and brief.
Giskard
CC BY-SA 4.0
2021-07-12T02:51:04.197Z
I'm sitting here with a mere 101 rep and can't downvote but this answer should be junked.
Joshua
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2021-07-12T22:34:54.420Z
@Joshua Therein lies the problem with HNQ on controversial topics. Regardless of whether one agrees with this particular answer, drawing in a bunch of 101 rep users from other SE sites on controversial questions leads to massively skewed voting, since the 101 rep users can upvote, but not downvote. This happens all the time on sites like Politics and Skeptics that get a lot of controversial topics. Personally, I think the upvote rep threshold should also increase to 125 while a question is on HNQ, at least on sites that frequently get controversial questions.
reirab
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2021-07-12T22:46:32.067Z
@reirab: Skeptics should not be on HNQ because they have a local policy the network as a whole disagrees with.
Joshua
CC BY-SA 4.0
2021-07-13T07:43:23.240Z
I should also note that if one is assessing this purely economically and trying to isolate 'moral' questions from away from the topic (boo, but economics has a bad habit of getting in trouble when it tries to encroach on moral philosophy) then we also need to factor in the utility of innocent prisoners getting whacked, and while the estimates vary, most fall into the "way too many" camp, and thus we have to evaluate the suffering caused by executing an innocent man against whatever the deterent effect might be. It doesnt bode well for capital punishments defenders.
Shayne
CC BY-SA 4.0
2021-07-10T09:50:44.793Z
2021-07-10T09:58:13.243Z
2021-07-10T09:58:13.243Z
Henry George
<p>Common sense says that the provision of death penalty would make it costlier for people to commit crimes like murder or rape, thus reducing the expected payoffs and accordingly the occurrence of such crimes. But I have also read articles that say that death penalty is not effective in practice and can even lead to some perverse results, for example, increasing the chances that a rapist murders the victim to reduce possibility of getting caught.</p>
<p>Is there a general consensus or if not consensus, widespread agreement on whether, when and why does capital punishment work or does not work in such cases, and other effects of it? Are there good recent reviews of the general state of research on this topic, especially about empirical papers that try causal inference?</p>

CC BY-SA 4.0
2021-07-10T20:18:46.817Z
The repeat-recidivism rate for murder is greater than zero. It follows that giving someone the death penalty for murder is 100% successful in preventing that individual from committing all future crimes, including that small proportion of murderers who go on to commit more murders after getting out.
Richard
CC BY-SA 4.0
2021-07-10T21:19:49.800Z
If "death" was a deterrent which was always more powerful that "staying alive, but not living in an acceptable environment", no human would ever commit suicide.
alephzero
CC BY-SA 4.0
2021-07-10T21:36:13.800Z
> Common sense says that the provision of death penalty would make it costlier for people to commit crimes like murder or rape, thus reducing the expected payoffs and accordingly the occurrence of such crimes. Consider a gangland criminal involved in a turf war with another gang. If he/she does not murder a rival gang member, the rival will murder him/her. So having got into this situation, not committing murder means the probability of death is 100%. On the other hand if he/she does commit murder in a jurisdiction which uses capital punishment, the probability of death is the probability of b
alephzero
CC BY-SA 4.0
2021-07-10T21:54:35.330Z
you might want to reduce the scope to "premeditated violent crimes"
njzk2
CC BY-SA 4.0
2021-07-12T14:45:56.393Z
For someone definition of "common sense," I guess
Azor Ahai -him-
CC BY-SA 4.0
2021-07-12T15:26:55.670Z
@Richard using the same reasoning the best treatment for any disease is death: 100% success that the individual won't be sick again. And if we generalize killing everybody solves every possible problem.
Erwan
CC BY-SA 4.0
2021-07-12T15:51:06.553Z
@Erwan - I think you've dramatically misunderstood the purpose of modern medical practice. The goal isn't to prevent future illness, it's to maximise the patient's standard of living (within an agreed budget). Killing your patient would result in a very low SoL score.
Richard
CC BY-SA 4.0
2021-07-12T15:55:12.523Z
@Erwan - That being said, I'm really rather in favour of the death penalty for all sorts of persistent repeat offenders. I'm fairly sure that burglers would burgle less if they knew that the next time they were caught they'd be executed.
Richard
CC BY-SA 4.0
2021-07-12T16:07:39.283Z
Why is this on topic for economics?
DJClayworth
CC BY-SA 4.0
2021-07-12T16:25:23.983Z
@Richard By definition a dead person doesn't even have a standard of *living*, so their SoL score is neither low or high: problem "solved". What I mean of course is that removing the symptom is not the same as addressing the problem, killing criminals is just a lazy way to pretend solving criminality. If it made any sense, there would be very little crime in countries with the death penalty and a lot of crime in countries without it, but that's not the case.
Erwan
CC BY-SA 4.0
2021-07-12T17:16:14.107Z
@DJClayworth - Because criminals cost society a buttload of money each year?
Richard
CC BY-SA 4.0
2021-07-12T20:06:51.323Z
@alephzero "Edge cases exist in which this principle is not 100% perfectly applicable, therefore it's no good" is a technique most commonly employed in bad faith to shut down discussion of a topic rather than addressing it on its merits.  Even if that's not your intention here, that's kind of what it looks like.  Please don't do that.
Mason Wheeler
CC BY-SA 4.0
2021-07-12T21:34:16.973Z
For what it's worth, the bit about "increasing the chances that a rapist murders the victim to reduce possibility of getting caught" would be highly jurisdiction dependent. At least in the U.S., no crime that does not result in death is punishable by death (since 1972,) so it's not possible for the death penalty to lead to such a perverse incentive unless murder (or other crime resulting in a victim's death) has already been committed.
reirab
CC BY-SA 4.0
2021-07-13T05:49:34.810Z
People who enlist in the military know that they are risking death, but people enlist anyway, often with great enthusiasm. That shows that the risk of death is not inherently a deterrent. It always depends on the perceived value of the action causing that risk, as well as the perception of the reality of that risk. That makes it not an economic question at all, but a psychological and emotional one.
Kevin Keane
CC BY-SA 4.0
2021-07-13T05:53:11.253Z
@Richard you can eliminate the recividism rate with life in prison. And you also have to balance it against the number of people who become first-time murders because they live in a culture that considers killing acceptable.
Kevin Keane
CC BY-SA 4.0
2021-07-13T07:47:41.107Z
@KevinKeane - People commit crimes in prison, you know
Richard
CC BY-SA 4.0
2021-07-13T07:48:29.587Z
If we're going to do the morals of the question from a proper economics approach, you need a metric, and the only useful one here is suffering. And thats *hard* when it comes to murder, because murdered people don't suffer. But people waiting 10+ years on death row do. And so does their poor suffering mother. Theres little proof that capital punishment reduces murder, but it *does* increase death, some of which might be innocent. All of which begs the question, what is this practice really *for*, if it increases suffering without reducing murder?
Shayne
CC BY-SA 4.0
2021-07-13T10:22:36.740Z
@DJClayworth Economics is all about responses to incentives. This question is about responses to incentives.
Criticize SE actions means ban
CC BY-SA 4.0
2021-07-14T13:16:12.870Z
@user253751 If anything about "responses to incentives" is on topic, can I ask a parenting question?
DJClayworth
CC BY-SA 4.0
2021-07-14T17:46:05.857Z
@DJClayworth As long as there are mathematical-statistical studies on the subject, so a precise, academically supported answer can be given, sure! You are also welcome to learn about our SE's rules.
Giskard
CC BY-SA 4.0
2021-07-14T17:53:12.813Z
The help page [What is on topic here](https://economics.stackexchange.com/help/on-topic) seems to assume that any questions will actually be related to economics. What other rules did you have in mind?
DJClayworth
CC BY-SA 4.0
2021-07-14T20:15:15.113Z
@DJClayworth Economic studies of crime and criminal behaviour are common actually, you can see papers from Economics journals cited in the answers to this question too. You can see Winter (2019) as a review of the general economic literature on crime. https://www.taylorfrancis.com/books/mono/10.4324/9780429467158/economics-crime-harold-winter
Ishan Kashyap Hazarika
CC BY-SA 4.0
2021-07-15T03:03:56.583Z
I agree. But this question isn't about that.
DJClayworth
CC BY-SA 4.0
2021-08-23T19:33:25.700Z
Here's a useful reference from Donohue and Wolfers, ["Uses and Abuses of Empirical Evidence in the Death Penalty Debate"](https://www.nber.org/papers/w11982)
jmbejara
CC BY-SA 4.0
2021-11-30T07:42:13.507Z
I’m voting to close this question because I do not think it is on topic.
Jesper Hybel
<reference-request><empirical-evidence>
The efficacy of death penalty in reducing violent crimes
Ishan Kashyap Hazarika
# The efficacy of death penalty in reducing violent crimes

(Asked by: username_0 on 2021-07-10)

Common sense says that the provision of death penalty would make it costlier for people to commit crimes like murder or rape, thus reducing the expected payoffs and accordingly the occurrence of such crimes. But I have also read articles that say that death penalty is not effective in practice and can even lead to some perverse results, for example, increasing the chances that a rapist murders the victim to reduce possibility of getting caught.

Is there a general consensus or if not consensus, widespread agreement on whether, when and why does capital punishment work or does not work in such cases, and other effects of it? Are there good recent reviews of the general state of research on this topic, especially about empirical papers that try causal inference?

**Tags:** reference-request, empirical-evidence
> **Comments:**
> **username_1**: The repeat-recidivism rate for murder is greater than zero. It follows that giving someone the death penalty for murder is 100% successful in preventing that individual from committing all future crimes, including that small proportion of murderers who go on to commit more murders after getting out.  
> **username_2**: If "death" was a deterrent which was always more powerful that "staying alive, but not living in an acceptable environment", no human would ever commit suicide.  
> **username_2**: > Common sense says that the provision of death penalty would make it costlier for people to commit crimes like murder or rape, thus reducing the expected payoffs and accordingly the occurrence of such crimes. Consider a gangland criminal involved in a turf war with another gang. If he/she does not murder a rival gang member, the rival will murder him/her. So having got into this situation, not committing murder means the probability of death is 100%. On the other hand if he/she does commit murder in a jurisdiction which uses capital punishment, the probability of death is the probability of b  
> **username_3**: you might want to reduce the scope to "premeditated violent crimes"  
> **username_4**: For someone definition of "common sense," I guess  
> **username_5**: @Richard using the same reasoning the best treatment for any disease is death: 100% success that the individual won't be sick again. And if we generalize killing everybody solves every possible problem.  
> **username_1**: @Erwan - I think you've dramatically misunderstood the purpose of modern medical practice. The goal isn't to prevent future illness, it's to maximise the patient's standard of living (within an agreed budget). Killing your patient would result in a very low SoL score.  
> **username_1**: @Erwan - That being said, I'm really rather in favour of the death penalty for all sorts of persistent repeat offenders. I'm fairly sure that burglers would burgle less if they knew that the next time they were caught they'd be executed.  
> **username_6**: Why is this on topic for economics?  
> **username_5**: @Richard By definition a dead person doesn't even have a standard of *living*, so their SoL score is neither low or high: problem "solved". What I mean of course is that removing the symptom is not the same as addressing the problem, killing criminals is just a lazy way to pretend solving criminality. If it made any sense, there would be very little crime in countries with the death penalty and a lot of crime in countries without it, but that's not the case.  
> **username_1**: @DJClayworth - Because criminals cost society a buttload of money each year?  
> **username_7**: @alephzero "Edge cases exist in which this principle is not 100% perfectly applicable, therefore it's no good" is a technique most commonly employed in bad faith to shut down discussion of a topic rather than addressing it on its merits.  Even if that's not your intention here, that's kind of what it looks like.  Please don't do that.  
> **username_8**: For what it's worth, the bit about "increasing the chances that a rapist murders the victim to reduce possibility of getting caught" would be highly jurisdiction dependent. At least in the U.S., no crime that does not result in death is punishable by death (since 1972,) so it's not possible for the death penalty to lead to such a perverse incentive unless murder (or other crime resulting in a victim's death) has already been committed.  
> **username_9**: People who enlist in the military know that they are risking death, but people enlist anyway, often with great enthusiasm. That shows that the risk of death is not inherently a deterrent. It always depends on the perceived value of the action causing that risk, as well as the perception of the reality of that risk. That makes it not an economic question at all, but a psychological and emotional one.  
> **username_9**: @Richard you can eliminate the recividism rate with life in prison. And you also have to balance it against the number of people who become first-time murders because they live in a culture that considers killing acceptable.  
> **username_1**: @KevinKeane - People commit crimes in prison, you know  
> **username_10**: If we're going to do the morals of the question from a proper economics approach, you need a metric, and the only useful one here is suffering. And thats *hard* when it comes to murder, because murdered people don't suffer. But people waiting 10+ years on death row do. And so does their poor suffering mother. Theres little proof that capital punishment reduces murder, but it *does* increase death, some of which might be innocent. All of which begs the question, what is this practice really *for*, if it increases suffering without reducing murder?  
> **username_11**: @DJClayworth Economics is all about responses to incentives. This question is about responses to incentives.  
> **username_6**: @user253751 If anything about "responses to incentives" is on topic, can I ask a parenting question?  
> **username_12**: @DJClayworth As long as there are mathematical-statistical studies on the subject, so a precise, academically supported answer can be given, sure! You are also welcome to learn about our SE's rules.  
> **username_6**: The help page [What is on topic here](https://economics.stackexchange.com/help/on-topic) seems to assume that any questions will actually be related to economics. What other rules did you have in mind?  
> **username_0**: @DJClayworth Economic studies of crime and criminal behaviour are common actually, you can see papers from Economics journals cited in the answers to this question too. You can see Winter (2019) as a review of the general economic literature on crime. https://www.taylorfrancis.com/books/mono/10.4324/9780429467158/economics-crime-harold-winter  
> **username_6**: I agree. But this question isn't about that.  
> **username_13**: Here's a useful reference from Donohue and Wolfers, ["Uses and Abuses of Empirical Evidence in the Death Penalty Debate"](https://www.nber.org/papers/w11982)  
> **username_14**: I’m voting to close this question because I do not think it is on topic.  

---

## 2 answers

### Answer by username_15 on 2021-07-10. Score: 40

The literature on this issue flip flops. The first seminal study by Sellin (1959)¹ did not find any significant effect, but early literature was riddled with methodological errors. Ehrlich’s (1975)² study at the time was far more sophisticated, and it showed a strong deterrent effect of capital punishment. However, ironically, this study later too became criticized for lack of empirical rigor (as the statistical method advanced). Cochran and
Chamlin (2000)³ and Lamperti (2008)⁴ showed that not only it did not deter violent crimes, but it could also have even increased them via the 'brutalization' effect. However, later Dezhbakhsh,
Rubin, and Shepherd (2003)⁵ employing panel data again showed it has a deterrence effect, but that study was later itself challenged by Kovandzic, Vieraitis, and Boots (2009)⁶.

New meta analyses show that evidence is somewhat mixed too. For example, meta analysis of Yang & Lester (2008)⁷ argues there is a significant deterrence on some crimes, but meta analysis of Dölling et al. (2009)⁸ finds that the effect of capital punishment on violent offenses is not significant. It is very hard to fish out the true effect because of endogeneity issues. Places in US with high violent rates often have capital punishment, is that because those places need the deterrent most or because it is ineffective deterrent and other places have better policies? Although it is matter of ongoing discussion most researchers now tend to lean more to the side that capital punishment is not effective deterrent but the research is not fully settled.

**References**

1. Sellin, Thorsten. 1959. The death penalty. Philadelphia, PA: American Law Institute.
2. Ehrlich, Isaac. 1975. The deterrent effect of capital punishment: A question of life and death.
   American Economic Review, 65: 397–417.
3. Cochran, John K. and Mitchell B. Chamlin. 2000. Deterrence and brutalization: The dual effects of executions. Justice Quarterly, 17: 685–706
4. Lamperti, John. 2008. Does capital punishment deter murder? A brief look at the evidence.
   Retrieved October 8, 2009 from math.dartmouth.edu/~lamperti/capitalpunishment.pdf
5. Dezhbakhsh, Hashem, Paul H. Rubin, and Joanna M. Shepherd. 2003. Does capital punishment have a deterrent effect? New evidence from postmoratorium panel data.
   American Law and Economics Review, 5: 344–376
6. Kovandzic, T. V., Vieraitis, L. M., & Boots, D. P. (2009). Does the death penalty save lives? New evidence from state panel data, 1977 to 2006. Criminology & Public Policy, 8(4), 803-843
7. Yang, B., & Lester, D. (2008). The deterrent effect of executions: A meta-analysis thirty years after Ehrlich. Journal of Criminal Justice, 36(5), 453-460.
8. Dölling, D., Entorf, H., Hermann, D., & Rupp, T. (2009). Is deterrence effective? Results of a meta-analysis of punishment. European Journal on Criminal Policy and Research, 15(1), 201-224.

> **Comments:**
> **username_16**: Interesting bit about the correlation between high crime prevalence and harsh laws. A conjecture coming to my mind is that such communities focus on the wrong things, namely ineffectual punishment instead of "soft" interventions that strengthen the social fabric and provide alternatives to a criminal career for young men. The Freaconomics drug dealer chapter anecdotally shows how being a low-earning, high-risk criminal is a rational decision when no other opportunities exist. The dealers directly risk their lives -- their death rate is higher than on death row -- but that does not deter them.  
> **username_17**: All these studies seem focused on the USA. I'm curious if there are any studies related to the execution of drug smugglers & the low crime rate in Singapore.  
> **username_18**: @axsvl77 If you look at international comparisions here you should also notice that every single European country does not have the death penalty and every single one of them has a much lower murder rate than the US. Singapore also has lower crime rates than the US and has the death penalty.  
> **username_17**: @quarague So are you saying there may be times when the death penalty does not work, and that there may be times when it does? I agree. OP asks "when and why does capital punishment work ". I think that your comment is the first look at actually answering this question.  
> **username_18**: @axsvl77 It seemed like you wanted to argue that the death penalty works by citing the example of Singapore. I think this would be a highly selective view as there are plenty of other countries with low crime rates without the death penalty. So it is not death penalty may or may not work but rather low crime rate can be achieved with or without death penalty.  
> **username_17**: @quarague History is complicated. I don't want to speculate about what studies related to Singapore's prolific executions might show. I just do know that this answer, despite the upvotes, does not answer the question because it is focused on only the USA. I was, and am suggesting that this answer should be expanded to include more information.  
> **username_9**: @axsvl77 Singapore is also a police state, and a very small single city that is easy to police. The risk of getting caught is extremely high (at the expense of a huge loss of privacy for the citizens). The low crime rate there may be more due to the near-certainty of getting caught than due to harsh punishments.  
> **username_17**: @KevinKeane OP asks "when and why does capital punishment work ".  So find sources for your comment, and make it an answer, and I will upvote you.  
> **username_15**: @axsvl77 if you are interested about Singapore maybe try asking a separate question about it. I focused on US because that is where most research on this was done. I wanted to focus on main literature in this answer, work on Singapore is quite niche, I can't even think about a widely known paper just from top of my head but for sure there must be some.  

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### Answer by username_19 on 2021-07-10. Score: 9

The death penalty as a deterrent to crime is ineffective is the prevailing view amongst researchers and experts in the field of criminology.
Some studies would indicate that there is no correlation between the death penalty and the reduction of violent crime. However, like any topic, you can find contrarian views that say there is no conclusive evidence to say that it does not. The increased use of econometric models is inconclusive aswell.

"The data alone cannot reveal what the homicide rate in a state without (with) a capital punishment regime would have been had the state (not) had such a regime."

"In their book, Professors Hood and Hoyle say almost all the academic studies available for review are concerned with the deterrent effect of capital punishment on the rate of murder in the United States.

The authors say theoretical and methodological issues have 'dogged the attempts to prove or disprove the existence of the deterrent effect of executions in the United States' and 'a fierce controversy continues' in the United States over attempts to use econometric models to address the question.

After reviewing the literature they conclude that 'it is not prudent to accept the hypothesis that capital punishment, as practised in the United States, deters murder to a marginally greater extent than does the threat and application of the supposedly lesser punishment of life imprisonment'."

"His position is shared by the majority of criminologists in relation to homicide, according to a 2009 survey of members of the American Criminology Society, who were asked to limit their answers to their understanding of the empirical research and to exclude their personal opinions. That study found that over 88 per cent of the criminologists did not believe the death penalty deterred murderers."

"A comprehensive review of the research in this area over 34 years was conducted in 2012 by a committee of the American National Academy of Sciences National Review Council. The committee concluded that "research to date on the effect of capital punishment on homicide is not informative about whether capital punishment decreases, increases, or has no effect on homicide rates"

* <https://www.abc.net.au/news/2015-02-26/fact-check3a-does-the-death-penalty-deter3f/6116030?nw=0>

Furthermore, as a penalty itself, the death penalty is morally repugnant and an anti-thesis to any government that would claim moral authority over its citizens.

Additionally, it is extremely costly as a form of punishment, some within the UN argue it can constitute torture and for its finality as a punishment, there is far too much human error involved in its delivery.

"From 1973 through December 2014, 150 innocent people were exonerated from death row"- <https://www.aclu.org/issues/human-rights/human-rights-and-death-penalty>

Then there are the issues within the legal institutions that would apply it, and the biases they hold.

• Jurors in Washington state are three times more likely to recommend a death sentence for a black
defendant than for a white defendant in a similar case. (Prof. K. Beckett, Univ. of Washington, 2014).
• In Louisiana, the odds of a death sentence were 97% higher for those whose victim was white than for those whose victim was black. (Pierce & Radelet, Louisiana Law Review, 2011).
• A study in California found that those convicted of killing whites were more than 3 times as likely to be sentenced to death as those convicted of killing blacks and more than 4 times more likely as those
convicted of killing Latinos. (Pierce & Radelet, Santa Clara Law Review, 2005).

In terms of economic analysis, I don't know if this is what you had in mind, but it is related, with cited research by economists who've endeavored to study the issue through that lens. Albeit from 1996

[https://digitalcommons.iwu.edu/cgi/viewcontent.cgi?article=1001&context=uauje#:~:text=The%20marginal%20economic%20cost%20of,to%20put%20somebody%20to%20death](https://digitalcommons.iwu.edu/cgi/viewcontent.cgi?article=1001&context=uauje#:%7E:text=The%20marginal%20economic%20cost%20of,to%20put%20somebody%20to%20death).

A small snippet from the above link - "In 1973, economist Isaac Ehrlich studied data from robberies that occurred in the 1940s,1950s, and 1960s. He found that the higher the probability of conviction for robbery, the
lower the robbery rate, ceteris paribus (Cooter and Ulen 1988). However, he found that the severity of the punishment did not affect deterrence in 1940 and 1960. Interestingly, he found a deterrent effect based on the severity of punishment when studying robbery reports from 1950. More recently the Capital Punishment Research Project and the New York Times compared capital and non-capital states to assess deterrence effects (Economist 1994a).The investigation examined the number of murders that occurred in New Jersey before and after the imposition of a death penalty statute in 1982. No statistically significant decrease was found in the number of murders that occurred. The study also compared the number of murders per 100,000 residents in both Massachusetts (a non-capital state) and New Jersey (presently a capital state). No significant difference was found in the number of murders. In the same study, the murder rate in New York (a non-capital state when the study was conducted) was compared to the rate in Texas (a capital state); and there was no statistical difference between the two states with respect to the number of murders per 100,000 residents. Interestingly, while most southern states have the death penalty, they also have higher murder rates. In fact, Louisiana, a capital state, has the highest murder rate in the nation. Among southern states, only Florida has a murder rate below the national average"

In terms of overall views on the subject, it differs highly in which country you are referring to, as it is not just a scientific issue, but a political one. There is also unfortunately a lot of ignorance and emotionally distorted reasoning when dealing with the topic with those unfamiliar with it.

> **Comments:**
> **username_15**: this answer just argues against the use of death penalty instead of answering the request for empirical literature review on its efficacy  
> **username_12**: Your answer has valuable information, it could be pruned a bit to make it more focused and brief.  
> **username_20**: I'm sitting here with a mere 101 rep and can't downvote but this answer should be junked.  
> **username_8**: @Joshua Therein lies the problem with HNQ on controversial topics. Regardless of whether one agrees with this particular answer, drawing in a bunch of 101 rep users from other SE sites on controversial questions leads to massively skewed voting, since the 101 rep users can upvote, but not downvote. This happens all the time on sites like Politics and Skeptics that get a lot of controversial topics. Personally, I think the upvote rep threshold should also increase to 125 while a question is on HNQ, at least on sites that frequently get controversial questions.  
> **username_20**: @reirab: Skeptics should not be on HNQ because they have a local policy the network as a whole disagrees with.  
> **username_10**: I should also note that if one is assessing this purely economically and trying to isolate 'moral' questions from away from the topic (boo, but economics has a bad habit of getting in trouble when it tries to encroach on moral philosophy) then we also need to factor in the utility of innocent prisoners getting whacked, and while the estimates vary, most fall into the "way too many" camp, and thus we have to evaluate the suffering caused by executing an innocent man against whatever the deterent effect might be. It doesnt bode well for capital punishments defenders.  

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