Evidence that the Death Penalty Deters
By
David Bragdon
( He is a graduate of Campbell University. He has majored in Government/Prelaw and minored in Economics, and he has started a law school.)
The death penalty seems to be a controversial issue for most people. Supporters claim that it eliminates repeat offenders, deters potential murderers, and is the ultimate retribution. Opponents denounce it as murder, say that it does not cause deterrence but rather promotes violence, and claim that it introduces the chance of an innocent person being executed.
Of all the arguments presented by both sides, one seems to be more compelling and crucial than the rest - deterrence. Will the use of the death penalty cause potential murderers to be less likely to commit murder? Deterrence may sound like a dull word, but think of the implications:
If the death penalty really causes deterrence, then using it decreases the number of murders and saves lives. If the death penalty saves lives, then we should use it more often to protect innocent victims. Why wait, why complain about the violence of it, if our friends, neighbors, parents, and children can be saved by punishing those we know to be guilty.
On the other hand, if the death penalty does not cause deterrence, if it does not save lives, then it may be of questionable value at all. As figure 1 points out, deterrence is a big factor in public support for capital punishment. This essay undertakes the question of whether or not the death penalty causes deterrence. It looks at the history of the death penalty in the United States, analyzes other studies about the death penalty and deterrence, and uses a simple empirical approach to test whether or not the death penalty deters.
Capital punishment has been used since ancient times to punish a variety of offenses. From the beginnings of the United States, it was the mandatory punishment for a number of crimes. However, as time went on the death penalty faced a number challenges. A small minority began to question whether the death penalty was right. Although most Americans still supported it, sometimes these people would end up on juries for capital cases, and as a result, people began to notice that juries were less likely to convict when the death penalty was the automatic punishment. This development lead to a weakening and changing of death penalty laws. States allowed the jury to choose the punishment, and some states abolished capital punishment altogether.
In 1967, the death penalty was suspended in order for the federal appellate courts to decide on its constitutionality. In 1972, in Furman v. Georgia, the Supreme Court ruled the death penalty unconstitutional in the way that it was being implemented. The Supreme Court ruled that states were applying the death penalty arbitrarily and irregularly. In one fell swoop, every death penalty law was rejected as unconstitutional. In 1976, in Gregg v. Georgia, the Supreme Court decided that the death penalty was not unconstitutional per se but states had to implement it fairly. However, the court made it difficult for states to reimplement the death penalty. In Woodson v. North Carolina, the court ruled that a mandatory death penalty for first degree murder was not a uniform standard. In 1976 and the years that followed states began to reinstitute the death penalty.
The first execution after the suspension in 1967 occurred in 1977. In 1979, two more executions occurred. The death penalty had some sporadic use between 1977 and 1983, but in 1984 there were 21 executions and in the years that followed there was a fairly steady amount of executions. However, even 56 executions - the highest number of executions in a single year - is an extraordinarily small number considering that in 1995 more than 2,000,000 people were beaten, knifed shot or otherwise assaulted each year, 23,000 fatally. Think about that for a second - 23,000 murders and only 56 executions - and 56 is the highest number since 1977. Thus, the year we had the most executions, there were 410 murders for every execution. Between 1977 and 1992 there were more than 338,780 murders (an average of 21,000 per year), but only 188 executions occurred. Thus, the execution rate is 0.00055 or 0.055%. In other words, the average is that for every 2000 murders, there is only one execution. The question arises, can the death penalty deter murder when it is used so rarely?
There are logical reasons to believe that the death penalty deters murder. Human nature causes one to fear getting caught and punished for offenses made. As a child, one learns that disobedience brings punishment. Punishment makes one less likely to break the rules. As a society, we use the same philosophy that our parents used by punishing those who commit crimes. People who rob banks, steal cars, kidnap kids, and murder victims are all going to face punishment for what they do. One of the effects of this punishment is that those contemplating crimes are less likely to commit them. That is why society doesn’t want fancy jails; it doesn’t want prison to be pleasant. In general, the worse the crime, the worse the punishment. Speeding carries only a fine and the threat of losing the privilege of driving. The more serious the crime, the more important it is to make punishment as strong and awful as possible so as to prevent people from doing it. In such a context, the death penalty makes perfect sense. It is the strongest punishment possible. Everyone has a natural fear of death. It makes sense to think that the death penalty would deter murder.
In an article from the American Journal of Sociology, David Philips says, "(1) Psychological experiments show that people are often deterred from exhibiting aggression when they see someone else punished for it…(2) there is anecdotal evidence that some criminals may have been deterred by the threat of capital punishment."
A further illustration makes the point even more clear. If the instant someone murdered someone else they died, the murder rate would be a fraction of what it is today. Only those killers willing to lose their life would commit the crime. In the same way, the death penalty can deter crime if used frequently enough.
Two additional pieces of evidence seem to indicate that the death penalty would deter murder. The first is that criminals convicted of murder 99.9% of the time ask to be sentenced to life in prison without parole rather than the death penalty. Obviously for them, being locked up all of one’s life is much better than facing death. If criminals fear that punishment worse, doesn’t it make sense that death would deter more than life in prison. The second piece of evidence is numerous documentation from criminals who said that the death penalty deterred them from committing murder.
All these facts are great, but the truth is murderers don’t die immediately upon killing a victim. As stated earlier, for every 2,000 murders there is only one execution. Think about the odds. If every student at Campbell University committed one murder, only one of us would be executed. The deterrence theory of crime states that in order for a punishment to deter, justice must be swift severe and certain. The death penalty is severe, but it is not certain and it is not swift. It takes an average of eight years in North Carolina from the time of sentencing to the time of execution to put a murderer to death. With the death penalty taking so long and being used so rarely, it would not be surprising to find little or no deterrence for its present form.
That is what this paper is trying to explore. 1. Does the death penalty in its present form deter murder? 2. Is it possible to increase the frequency of death penalty use in the hope that more deterrence will occur. The focus of this paper is on the first question, but the second question is addressed in appendix C. (Den som önskar läsa D. Bragdons Appendix kan begära webbadress från mig, D.A.)
Many political scientists have done studies on whether or not the death penalty causes deterrence. These studies are often conflicting. In fact, Walter S. McManus says that whether or not a researcher finds that the death penalty causes deterrence depends on a researchers prior beliefs. His conclusions state that the evidence for or against the deterrence of the death penalty is not strong enough to bring researchers to a consensus. Their results are highly dependent on whether or not they accept executions as an indicator. Rejecting executions as an indicator will lead to results showing no deterrent effect. Thus, researchers who oppose the death penalty will not use executions as an indicator.
Although prior beliefs may have some influence in a researchers results, I think it is important to look at studies and analyze the way in which they were conducted. An article in the Economist opposing capital punishment said that the death penalty didn’t deter because those states that used the death penalty didn’t have lower murder rates than states that didn’t use the death penalty. This method of analysis is highly used among those who oppose the death penalty, but as this paper will show, it does not have validity. The article also highlighted states that had low murder rates not using the death penalty, and states that had no change in their murder rate that used the death penalty.
William C. Bailey shows that televised coverage of executions does not have an effect on homicide rates. His study only looks at the short-term effects, and does not look to see if there is a long term effect among states that use the death penalty.
David Phillips of University of California found that after the news covered an execution the murder rate would go down that week, but it was only temporary with no apparent long-term affects.
…
Hugo Adam Bedau (abolitionist) said in his study that the death penalty did not cause deterrence now and it was not capable of causing it at all because it would be impossible for a country like the United States without judicial system to implement the death penalty consistently and quickly to have an effect. He also compared the murder rate with states that have the death penalty to states that don’t have it. In addition, he compared the murder rate of states bordering one another. Like other opponents of the death penalty, his research did not separate the death penalty from a host of other factors that could affect the murder rate.
In 1975, a man by the name of Isaac Ehrlich did a study showing that the death penalty caused deterrence. He used time series evidence. His methods used an economic kind of analysis to show that as the change of arrest, conviction, and execution went up, homicides went down. He used data from the United States, Canada, England, and Wales. Testing all of these countries, he found the same results. His results were highly controversial and challenged by many opponents of the death penalty. The source of his data was challenged among other things.
In 1985, Stephen Layson, a professor at University of North Carolina at Greensboro set out to see if he could clear up the controversy. He repeated Ehrlich’s study using better data and slightly different methods. He found the same results that Ehrlich had found. "The regression results consistently support the deterrence hypothesis that increases in the probabilities of arrest, conviction, and execution reduce the homicide rate. Even murderers appear to obey the law of demand.
James Peery Cover and Paul D. Thistle also reviewed Ehrlich’s study. They found that he had not taken into account the fact that the United States "homicide rate follows a nonstationary stochastic process, and that the data must be differenced to achieve stationarity." In other words, they felt the homicide rates were random and not related to the deterrence from the death penalty. They conceded that deterrence might be present, but that it was ambiguous.
Having reviewed other studies, we come to my study. My question is, has the death penalty in its present form deterred murder in the states that used it between 1979 and 1995. My hypothesis was twofold. The death penalty does deter murder, even in its present form. The relationship will be relatively weak because the death penalty is used so rarely in the United States. I had two variables that needed to be measured, the death penalty and deterrence. The conceptual definition of death penalty that I used is the punishment of execution for a crime. I used five indicators to determine how much each state really used the death penalty.
The first indicator is the number of executions a state held between 1979 and 1995. I felt that the more executions a state held the greater the decrease would be in that state’s murder rate. States such as Texas and Florida with large numbers of executions would have more success in lowering their murder rate.
The second indicator is the number of years during which executions were held in a state.. States that held executions almost every year would have a high number. More than the number of executions I thought would be important. If a state held executions nearly every year, it would be more likely to have a decrease in its murder rate.
The third indicator is the number on death row is the number of prisoners on death row in 1995. This indicator may be weaker because many states put lots of killers on death row but never execute them. Since I felt deterrence would be based more on executions, I expected this indicator to be weaker.
The fourth indicator is the ordinal strength, a ranking of the states by how often thy hold executions. States that have put no one on death row or held no executions are ranked 1. States that have put criminals on death row, but have executed no one are ranked 2. States that have held executions less than five out of the last seventeen years are ranked 3. States that have held executions five ore more out of the last seventeen years are ranked 4.
This ordinal category was added because it gave states that had put people on death row but not held executions a place for analysis. This indicator is based on indicator number two. However, indicator number two ranks all states that haven’t had an execution as 0. This indicator gives a value to states that put prisoners on death row, but do not execute. Hence, if just having the death penalty and putting criminals on death row but not executing them causes deterrence, then I would expect this indicator to be slightly stronger than indicator number 1.
The fifth indicator is the legality of the death penalty. This is simply whether or not the death penalty is legal in a state. I suspect it to be weaker since mere legality is not a good measure of the death penalty.
My conceptual definition of deterrence is when a population commits fewer crimes because of fear of punishment. My indicator for this was the percentage change in the murder rate per 100,000 between 1979 and 1995. My indicators are both reliable and valid. They are reliable because anyone can look up the statistics and find exactly the same data. They are valid because they accurately reflect my concepts. My source of data was the World Almanacs from 1980 to 1996. I compiled the murder rate per 100,000, the number of executions, and the number of people on death row for each year for each state.
As the reader can easily see, this is a relatively simple test to determine whether or not the death penalty deters murder. It uses the current period and has the advantage of starting at a point when the death penalty was just beginning to be used again from a ten year break. In 1979, the death penalty had still not quite risen from the grave. The murder rate for every state was exactly what it would be in absence of the death penalty. Some states enacted capital punishment and some states didn’t. Hence, one is in a perfect position to compare the changes between the states that adopted the death penalty and the states that didn’t. If the death penalty deters, the murder rate would decrease more in states that used it frequently than in states that used it rarely or not at all. By using the change in the murder rate, I had gone a long way in isolating it from other influences that might change the murder rate apart from the death penalty. I emphasized executions because if the death penalty is never used, there is no real threat, no fear, and hence no deterrence. I compared each one of my indicators for the death penalty with my indicator for deterrence. I computed Pearson’s "r" to indicate the degree of relationship between the two variables.
As noted before, many analysises of the effect of deterrence on the death penalty simply compare the murder rate of states that have the death penalty with the murder rate of states that do not have the death penalty. This is not a valid comparison. People who support the deterrence theory of the death penalty do not claim that death penalty states will automatically have lower murder rates than non-death penalty states. They only claim that death penalty states will have a lower murder rate than they would have had otherwise. Many other factors affect the murder rate in a state, factors such as population, urbanization etc. Thus, just because Texas has a higher per capita murder rate than Hawaii or North Dakota, doesn’t necessarily mean that the death penalty doesn’t deter. The murder rate could be due to size, population, climate, or a combination of many trends of which the death penalty is only a small factor.
The death penalty indicators are numbers 1 through 5. The deterrence indicator is number 6. These correspond with the indicators mentioned earlier. 1. Shows how many executions a state held between 1979 and 1995. 2. Shows the number of years in which a state held at least one execution between 1979 and 1995. 3. Shows the number of people on death row in 1995. 4. Is an ordinal ranking of the death penalty in a state, 1 being a state that has never used the death penalty and 4 being a state that uses it a lot. 5. Is simply whether or not a state has the death penalty. 6. Shows the percentage change in the murder rate between 1979 and 1995. A positive number means an increase in the murder rate. A negative number means a decrease in the murder rate.
Indicators 1, 2, and 4 had statistically significant results. As I suspected, it was the executions that deterred murder not just the presence of the death penalty itself.
For the first indicator, probability is .045, r is -.242. r2 = .0586. This means that there is a weak negative relationship between the change in the murder rate and the number of executions held. The more executions a state holds, the more likely it is that the murder rate will go down. r2 is a Proportional Reduction in Error measure. This means that one can reduce his error in predicting the dependent variable by 5.86% by knowing the independent variable. Thus, if one knows how many executions a state has had, he will be 6% more likely to guess the correct percentage change in the murder rate.
For the second indicator, probability is .034, r = -.261; r2 = .0681. Again, like before there is a weak negative relationship. As states hold executions more frequently there is a greater decrease in the murder rate. The PRE measure is .0681 meaning that by knowing the frequency of executions, one can reduce error in predicting the change in murder rate by 6.81%.
For the third indicator, probability is .098; r = -.186; r2 - .0345. Normally this would be considered a statistically insignificant relationship. However, this is not a sample, it is the entire population. Hence, the probability is not important. However r and r2 indicate that the relationship is very weak. It is much weaker than the last two indicators. There is not much of a relationship between the murder rate and the number of criminals on death row.
For the fourth indicator, probability is .030; r=-.267; r2 = .0712. There is another negative relationship similar to the first two variables. It is easy to see that the data for this indicator is similar to the data for the second indicator. Remember that the ordinal categories used in this indicator are based on the second indicator. It makes sense that the level of significance and the measure of Pearson’s "r" would be similar. However, the measure here is stronger than the second indicator. In giving states that have the death penalty but do not execute anybody a slightly higher rating we find that that the value of r increases slightly. This may be an indicator that although not nearly as strong, simply having the death penalty and putting people on death row is better than not having it at all.
The final indicator is the legality of the death penalty. Probability is .218; r = -.113; r2 = .0128. This last indicator is the weakest of all. Probability although not authoritative in this case, is way above accepted levels. r and r2 are extremely weak. One cannot reject the null hypothesis that there is no relationship between the legality of the death penalty and the change in the murder rate. Furthermore, anyone who uses mere legality as a measure of the death penalty will be giving the false impression that no relationship exists between the death penalty and deterrence when other more valid indicators show otherwise. The legality of the death penalty is not a valid indicator, and it is not significant.
In conclusion there is a relationship between the number and frequency of executions and the change in the murder rate. This relationship is moderately weak, but it is stronger than I predicted.
Another way to analyze whether or not the death penalty deters is through case studies. By looking at the states which have used the death penalty the most, one can see a distinct pattern. The states that used the death penalty the most had the biggest decrease in their murder rate.
Delaware had the highest per capita number of executions. It’s murder rate decreased by 38.6%. Missouri held 15 executions and held executions 6 out of the last 17 years. It had a 38.6 percent decrease in murders. Florida held 37 executions and 14 years. It had 40.2% decrease in crime. Texas with 84 executions had a 46.1 decrease. Georgia had 12 executions and a 44.4% decrease in the murder rate. Nevada all had executions six out of seventeen years and it had a 39.1% decrease in the murder rate. On the other hand, the states with high increases are often represented by states that do not have the death penalty, such as Vermont that had a 57.0% increase in the murder rate.
Other case evidence supports the deterrence theory. In 1981, Houston (Harris County), Texas had a high murder rate with 701 murders that year, more than the entire state of North Carolina. In 1982, Texas adopted the death penalty, and Houston executed more murderers than any other county or state. Their murder rate dropped considerably to 261 in 1966 - almost a third of what it had been, a 63% reduction. Another example is in England. In the 1920s and 1930s England was known as being a strong death penalty country. Even though the United States executed about 200 people every year, England executed more and had a lower murder rate than any one of our major cities at the time. Since England abolished capital punishment, their murder rate has doubled, and 75 citizens have been murdered by released killers. In Australia, over the period 1964-1973, the Australian states which executed the highest proportion of convicted murderers, had the lowest average homicide rates per 100,000 population in Australia during those years.
Is there a causal relationship between executions and the murder rate? In order for there to be a causal relationship several criterions must be true. There must be a relationship. This, as we have seen through Pearson’s "r" and the scatterplots is true. There must be plausibility as I discussed earlier. It makes sense that the death penalty would cause deterrence. People have a natural fear of punishment. Strong punishment deters any crime. The death penalty is the strongest punishment, plausibility is present. There must be precedence, in other words the death penalty must occur before the change in the murder rate. This is certainly true. There must be consistency - the relationship must be consistent with other indicators. Given Ehrlich and Layson’s studies, I think my study has consistency. However, the last requirement of causality is that there be no other possible cause. At this point, I have not done enough research to show that there is no other possible cause.
In conclusion, my study shows that there is a relationship between the number and frequency of executions and the change in the murder rate. This relationship may be causal, but more research is required to say anything with certainty. However, I do feel that there is enough of a logical link between the death penalty and deterrence to call for an increased use of the death penalty.
When George Washington and the continental soldiers were fighting in the Revolutionary War, it would have sounded strange to ask them if they enjoyed killing people and if they took pleasure in seeing their friends die. George Washington didn’t want people to die, but he knew that war was the only way freedom could survive. This is an issue about protecting our freedom to live. By implementing capital punishment more seriously, we are fighting the war to protect our freedom, instead of throwing down our weapons and saying that Capital Punishment is inhumane.
1997
By permission of David Bragdon
http://w1.155.telia.com/~u15509119