Deterrence Research Paper

The basic phenomenon is the fear of punishment. This fear may be influenced by the experience of punishment. When an offender has been punished he knows what it is like to be prosecuted and punished, and this may strengthen his fear of the law. The experience may, however, work the other way. It is conceivable that the offender previously had exaggerated ideas of the consequences of being caught and now draws the conclusion that it was not as bad as he had imagined. In this case, the special deterrent effect of the punishment is negative. More important, probably, a person who has been convicted of a somewhat more serious crime, and especially one who was sentenced to imprisonment, will have less to fear from a new conviction, since his reputation is already tarnished. In practice, it will be difficult or impossible to isolate the deterrent effects of the prison experience from other effects of the stay in prison. What we can measure is how offenders perform after punishment, expressed in figures of recidivism.

The Broad Sense: The Moral Effects of Criminal Law

In a broad sense, deterrence is taken to include not only the effect of fear on the potential offender but also other influences produced by the threat and imposition of punishment. Criminal law is not only a price tariff but also an expression of society’s disapproval of forbidden behavior, a fact influencing citizens in various ways. Most people have a certain respect for formal law as such. Moreover, the criminalization of a certain type of behavior may work as a moral eye-opener, making people realize the socially harmful character of the act (‘‘the law as a teacher of right and wrong’’). The moral condemnation expressed through the criminal law may also affect the moral attitudes of the individual in a less reflective way. Various labels are used to characterize these effects: the moral, the educative, the socializing, the attitude-shaping, or the norm-strengthening influence of the law. From the legislator’s perspective, the creation of moral inhibitions is of greater value than mere deterrence, because the former may work even in situations in which a person need not fear detection and punishment. In the Scandinavian countries and Germany the moral component in general prevention is considered to be essential. For the moral effect of criminal law the perceived legitimacy of the system, rooted in the application of principles of justice, proportionality and fairness, are regarded as more important than severity of sentences.

General Deterrence and General Prevention

 In continental literature general prevention is used as a technical term that denotes both the effect of fear and the moral effect of the criminal law. This is equivalent to general deterrence in the broad sense, but the term deterrence tends to focus on the effect of fear. Most American research papers on deterrence do not mention the question of definition but do in fact work with the broad concept, since they are concerned with all effects on crime rates of the system of criminal justice and make no effort to exclude effects produced through mechanisms other than fear.

Habituative Effects of Criminal Law

Much law-abiding conduct is habitual, and the threat of punishment plays a role in this habit formation. It is sufficient to mention the response of drivers to traffic signals. In a broad sense deterrence can be taken to include also the habituative effects of the law. Habit formation is, however, a secondary phenomenon. For a habit to be established, there must first be compliance based on other sources, which may include fear and respect for the law. The habit is eventually formed through repetition of the law-abiding conduct.

A Historical Perspective

Historically, deterrence has been, along with retribution, the primary purpose of punishment. The deterrent purpose has often led to penalties that, to contemporary minds, seem cruel and inhuman. Capital punishment and corporal punishment were the backbone of the systems of criminal justice up to the late eighteenth century. Executions were made public spectacles, and cruel methods of execution were often invented in order to enhance the deterrent effect.

In the eighteenth century the writers of the classical school of criminal justice—notably Cesare Beccaria in Italy, Jeremy Bentham in England, and P. J. A. von Feuerbach in Germany— based their theory of criminal law on general deterrence. The central idea was that the threat of punishment should be specified so that in the mind of the potential lawbreaker the fear of punishment would outweigh the temptation to commit the crime. The penalty should be fixed by law in proportion to the gravity of the offense. The certainty of punishment was considered as more important than the severity of the punishment. According to the classical theory, the penalty in the individual case had as its primary function to make the threat of the law credible. Only occasionally did these writers mention the moral effects of the criminal law.

In the late nineteenth century and the first half of the twentieth century the idea of deterrence lost ground to the idea of treatment and rehabilitation. Criminologists and penologists voiced the view that the most important aim of punishment was to correct the offender and, if this proved impossible, to incapacitate him. Therefore, the penalty had to be adjusted to the needs of the individual offender. In the United States the indeterminate sentence was introduced. The idea of the indeterminate sentence is based on an analogy to medical treatment in a hospital. The offender should be kept as long as necessary in order to cure him, no shorter, no longer; and just as with a stay in a hospital, the duration should not be decided in advance but on the basis of the observation of progress. On the European continent, measures of safety and reform for certain categories of offenders were introduced, based on similar ideas. The idea of deterrence was often ridiculed as fictitious, outmoded, and the cause of much unnecessary suffering. The saying ‘‘Punishment does not deter crime’’ was often accepted as established truth.

Although these ideas were dominant in the professional literature up to the 1950s, legislators, prosecutors, and judges continued to have faith in deterrence. From the early 1960s a change in criminological thought began to take place and gradually gained momentum. Research into the differential effects of various sanctions led to great skepticism with regard to society’s ability to rehabilitate offenders. It appeared that choice of sanction had very little effect when compared to the personality and background of the offender and to the social environment he went back to after his encounter with the machinery of justice. Moreover, it seemed that no one was able to tell when to release the offender in order to maximize his chances of a law-abiding life in the future. At least for the overwhelming majority of offenders, the hospital analogy does not work.

Two tendencies have emerged: a movement in favor of fixed sentences in proportion to the gravity of the offense, as demanded by the classical school of criminal law (‘‘neoclassicism’’); and a revival of interest in deterrence. When faith is lost in the idea of treatment and rehabilitation as the basis for a system of criminal sanctions, other aims of punishment come into focus. Up to 1965 the only empirical research in deterrence consisted of a few papers on the death penalty. Since the mid-1960s a series of books and a stream of research papers have been published on the subject, mainly in the United States, Canada, and Great Britain, but also in Germany, the Netherlands, and Scandinavia (see Beyleveld). Most research has been undertaken by either sociologists or economists. The economists, following the lead of Gary Becker, look upon the risk of punishment as a cost of crime and apply econometric methods to find out how a change in the price affects the rate of crime (Eide).

Empirical and Ethical Questions

In discussing deterrence one is confronted with two categories of questions. One category consists of empirical or factual questions: Does deterrence work, and if so, how well, in which fields, and under what circumstances? Another category consists of ethical questions: To what extent is the purpose of deterrence a valid moral basis for lawmaking, sentencing, and the execution of sentences? A penalty may be effective as a deterrent yet unacceptable because it is felt to be unjust or inhumane. The position on such questions as capital punishment, corporal punishment, and the length of prison sentences is dependent not only on views on efficacy but also on moral considerations. Even if it were possible to prove that cutting off the hands of thieves would effectively prevent theft, proposals for such a practice would scarcely win many adherents in the Western world today. Much of the discussion on deterrence has been of an emotional nature and has not separated the empirical questions from the value questions. Often people have let their views on empirical questions be heavily colored by their value preferences instead of basing them on a dispassionate scrutiny of the available evidence (Andenaes, 1974, pp. 41–44).

General Deterrence: Myth or Reality?

The strongest basis for the belief in deterrence is the eminent plausibility of the theory from the viewpoint of common sense. That the foresight of unpleasant consequences is a strong motivating factor is a familiar experience of everyday life. It would be a bold statement that this well-known mechanism of motivation is of no importance in the decision to commit or not commit an offense. Most offenders, and even more so most potential offenders, are within the borders of psychological normalcy. There is no prima facie reason to assume that they are insensitive to negative inducements.

Historical experiences from police strikes and similar situations show that even a short breakdown of criminal justice leads to great increases in offenses such as burglary and robbery (Andenaes, 1974, pp. 16–18, 50–51). By introspection many know that the risk of detection and negative sanctions plays a role for their own compliance with rules about taxation, customs, drinking and driving, and other traffic offenses. It seems to be a universal experience that police regulations that are not enforced gradually cease to be taken seriously. Paradoxically, the consequences of police corruption can be mentioned as a demonstration of the deterrent impact that the criminal law has when the machinery of justice is working normally and properly (Andenaes, 1975, pp. 360–361). All available data indicate that organized crime flourishes most where the local police have been corrupted. Police corruption paralyzes enforcement and gives professional criminals a feeling of immunity from punishment. That crime flourishes when the criminal justice system is paralyzed through corruption is another way of stating that a criminal justice system that works normally does deter crime, or at least some forms of crime, to some degree.

It seems safe to conclude that criminal law and law enforcement play an indispensable role in the functioning of a modern, complex society. However, from a practical point of view, this insight is of limited value. Policymakers are not confronted with the choice of retaining or abolishing the whole system of criminal justice. The choices are of a much more narrow kind. The legislator sometimes has the choice between criminalization or decriminalization of a certain type of behavior, such as homosexual conduct, abortion, pornography, or blasphemy. More often the choice is between a somewhat stricter or milder penalty or between somewhat higher or lower appropriations for the police or other control agencies. For the police, the prosecutor, the judge, and the prison administrator the choices are still more limited. The questions of practical importance do not refer to the total effects of criminal law but to the marginal effects of this or that change in the level of punishment or the allotment of resources (Zimring and Hawkins, pp. 7–8). These effects are difficult to foresee. Decisions on whether to change or not to change are often made on the basis of overly simplistic assumptions.

Factors in Deterrence

Severity and Credibility of The Threat

According to common sense, the motivating force of the threat of punishment will normally increase with the severity of the penalty and the risk of detection and conviction. It is a fair assumption that most offenses would not have been committed if the potential offender foresaw a 50 percent risk of being detected and receiving a severe prison sentence. Even in this situation there would, of course, be exceptions: cases of psychopathological crime, crime under extreme emotional stress, certain political crimes, and so on.

Since Beccaria it has been generally accepted that certainty of punishment is more important than severity, and research gives some support for this assumption. Such a simple formula needs qualifications. For example, in the field of white-collar crime a fine may be considered merely a business expense, whereas a prison sentence, through its stigmatizing character, may act as a strong deterrent. But if the level of penalties is already high, it seems probable that further increases in severity will yield diminishing returns. Moreover, excessively severe penalties may be counterproductive by reducing the risk of conviction. When the penalties are not reasonably attuned to the gravity of the violation, the public is less inclined to inform the police, the prosecuting authorities are less disposed to prosecute, and juries are less apt to convict.

Experience in Finland in the postwar years indicates that the general level of sentencing has a limited influence on deterrence. At the beginning of the 1950s the prison rate in Finland was about four times higher than in the Scandinavian neighboring countries (Denmark, Norway, Sweden). Since then the Finnish authorities systematically have endeavored to reduce the use of prison. Through decriminalization of offenses (most important public drunkenness), shorter sentences, more use of suspended sentences, community service, and heavy fines, the prison population has gradually decreased. In the 1990s it was on the same level as in the other Scandinavian countries, in which the prison rate has remained fairly stable (between 50 and 60 per 100,000 inhabitants).

Despite the great reduction of imprisonment in Finland the crime trend has been the same in all countries. The amount of crime has increased, but the curves are strikingly symmetric (LappiSeppälä, 1998). It should be added that the incapacitative effect of imprisonment plays a minor role in the Scandinavian countries as compared with the United States, which has much longer sentences and a prison population that is at least ten times higher (about 650 per 100,000 inhabitants in 1998).

The Problem of Communication

The motivating effect of criminal law does not depend on the objective realities of law and law enforcement but on the subjective perception of these realities in the mind of the citizen. A change that is not noticed can have no effect. If we intend, for example, to increase the deterrent effect in a certain field by more severe sentences or increased police activity, a crucial question will be whether people will become aware of the change. This aspect did not attract much attention in the classical theory of deterrence. It seemed to be tacitly assumed that there would be an accord between objective facts and subjective perceptions. Survey research into public beliefs and attitudes has demonstrated that this is far from the case. Smaller changes tend to go unnoticed whether they tend toward increased severity or leniency.

Types of Offenses

The importance of deterrence is likely to vary substantially, depending on the character of the norm being protected by the threat of punishment. Common sense tells one that the threat of punishment does not play the same role in offenses as different as murder, incest, tax fraud, shoplifting, and illegal parking. One distinction of importance is between actions that are immoral in their own right, mala in se, and actions that are morally neutral if they were not prohibited by law, mala prohibita. In the case of mala per se, the law supports the moral codes of society. If the threat of legal punishment were removed, moral feelings and the fear of public judgment would remain as powerful crime-prevention forces. In the case of mala prohibita the law stands alone; without effective legal sanctions the prohibition would soon be empty words. There are, however, great variations within each of the two groups. As Leslie Wilkins stated, ‘‘The average normal housewife does not need to be deterred from poisoning her husband, but possibly does need a deterrent from shoplifting’’ (p. 322). A realistic appraisal of the role of deterrence demands a thorough study of the specific offense and the typical motivation of violators.

Differences Among Persons

People are not equally responsive to legal threats. Some are easily deterred, others may lack the intellectual or emotional ability to adjust their behavior to the demands of the law. Children, the insane, and the mentally deficient are for this reason poor objects of deterrence. The same holds true for people who lack the willpower to resist the desires and impulses of the moment, even when realizing that they may have to pay dearly for their self-indulgence. Individuals who are well integrated into the social fabric have more to lose by conviction than those on the margin of society. When experts and political decision-makers discuss the deterrent impact of the threat of punishment, there is always a risk that they may draw unjustified conclusions on the basis of experience limited to their own social groups.

Conflicting Group Norms

The motivating influence of the criminal law may become more or less neutralized by group norms working in the opposite direction. One may think of religious groups opposing compulsory military service, organized labor fighting against a prohibition of strikes, or a racial minority fighting against oppressive legislation. In such cases there is a conflict between the formalized laws of the state and the norms of the group. Against the moral influence of criminal law stands the moral influence of the group; against the fear of legal sanction stands the fear of group sanction, which may range from the loss of social status to economic boycott, violence, and even homicide. Experience shows that the force of the group norm often prevails. In an atmosphere of alienation and antagonism, any attempt at law enforcement, even a well-justified and lawful arrest, may be the signal for an outbreak of violence and disorder, as was the case with the Watts riot of 1965 (President’s Commission, pp. 119–120).

Methods of Research

In spite of the great importance accorded deterrence in lawmaking and sentencing, deterrence remained a neglected field of research until about 1970, in part because of ideology and in part because of great methodological difficulties. In subsequent years research activity has been intense. Most of the research falls under the following categories.

Comparison Over Time

The most straightforward method of exploring the effects of a change in legislation or enforcement on the rate of crime is before-and-after research. The great difficulty in such research is to identify the impact of the change among all the other factors that have been involved at the same time. Only abrupt and major changes can be expected to give clear statistical evidence of the effects. Changes introduced in the criminal justice system may be accompanied by changes in the tendency of the victims to report the crime or by changes in the practice of crime recording by the police, so that the statistics are not comparable. These difficulties can, to some degree, be overcome by victimization studies undertaken both before and after the reform.

Perhaps the best-known example of before-and-after research was conducted in Great Britain in connection with the Road Safety Act of 1967, which made it an offense to drive with a blood alcohol concentration of 0.08 percent or more. The penalty is normally a fine and loss of driving license for one year on the first offense. From the day the new legislation went into effect, there was a considerable drop in highway casualties as compared with previous years. For the first three months casualties were 16 percent lower than in the preceding year, and deaths were down by 23 percent. For the night hours casualties were reduced by about 40 percent. Unfortunately, it seems that most of the effect has gradually been lost. As time passed it became increasingly difficult to isolate the effects of the law, but H. Laurence Ross’s conclusion seems well founded: the benefits produced by the legislation had largely been canceled by the end of 1970 (p. 77).

According to Ross, the explanation of this declining effect lies in a lack of enforcement. The publicity accompanying the law had given the public exaggerated and quite unrealistic ideas about the risk of apprehension and conviction, but little effort was made to enforce the law. The police did not perceive the law as defining an important task, and gradually the public learned that it had overestimated the risk.

The crucial importance of the risk of detection in this area is convincingly demonstrated by the effects of the Finnish reform of drinking-and-driving legislation in 1977 (Andenaes, 1988, pp. 42–63). Before the reform Finland had the most severe sentences for drunken driving among the Scandinavian countries, with prison sentences of several months. After the reform the great majority of offenders got fines or suspended prison sentences. At the same time a fixed limit of 0.05 percent blood-alcohol concentration was established, and the amount of random breath tests of drivers was drastically increased, from about 10,000 in 1977 to about 700,000 in 1984. Roadside surveys of a representative sample of drivers showed that the proportion of motorists driving under the influence of alcohol after the reform had been reduced to about half. The number of alcohol-related accidents also had diminished, although not to the same degree. The main reason for this probably is that many alcohol-related accidents are caused by drivers who have serious alcohol problems and do not react to the threat of punishment in the same way as average drivers.

Comparison Between Geographic Areas

A second method is to compare areas with differences in legislation, in sentencing, or in law enforcement, to see whether these differences are reflected in crime rates. This method was used in research on capital punishment as early as the 1920s, by comparing murder rates in retentionist and abolitionist states. Beginning in the late 1960s the method of geographical comparison has been widely used for different types of crime, by both sociologists and economists, who have employed various statistical techniques in order to discover the effects of differences in certainty and severity of sanction. Most of the American studies use the individual states as units of comparison, are based on official statistics, and are limited to the seven index crimes (homicide, assault, rape, robbery, burglary, larceny, and auto theft, as enumerated by the Federal Bureau of Investigation).

The research has almost invariably found an inverse relationship between certainty of punishment (or rather certainty of imprisonment) and crime rates. Some, but not all, of the researchers have found a similar but mostly lower relationship between severity of punishment (normally measured in length of prison sentences) and crime rates. The findings are, however, difficult to interpret. A few points should be mentioned:

1. Many of the studies do not try to distinguish between effects of deterrence and effects of incapacitation. The effects they ascribe to deterrence may in fact be a result of the incapacitation of offenders sentenced to prison.
2. A correlation between crime rates and severity and certainty of sanction does not in itself say anything about the direction of causality. Crime rates may influence severity or certainty of sanction as well as the other way around. The correlation may also be the result of a third factor, for example, the normative climate in a society. Few of the studies tackle these problems in a wholly satisfactory way.
3. The statistical equations have certain built-in assumptions that are not necessarily true.
4. If a study does not find a correlation between crime rates and severity or certainty of sanction, this does not prove that the differences in severity or certainty are without effect but only that in the given sample the effect is not of a sufficient magnitude to be statistically demonstrable.
5. As noted previously, official crime statistics fail to account for variations in rates of victim reporting and police recording of offenses. A low crime-reporting and/or recording rate tends to simultaneously lower the official crime rate, while raising the apparent rate of imprisonment; a high reporting or recording rate has the opposite effect. These variations naturally tend to produce a spurious inverse relationship between official crime rates and imprisonment rates.

For these and other reasons the comparative research should not be accepted uncritically. The highly technical character of such research also constitutes a barrier against practical application until a high degree of agreement among researchers is reached.

Survey Research

Survey research can be of interest to the theory of deterrence in many ways. The simplest form of such research consists in collecting data on public knowledge and beliefs about the system of criminal justice. Studies have generally found that such knowledge is low and haphazard. Comparisons over time or between geographical areas of such surveys can be used to explore how perceptions of severity and certainty of punishment vary with actual severity and certainty.

The survey method seems especially suitable for research into the moral effects of criminal law. Attitude surveys in England before and after introduction of the blood-alcohol limit (Sheppard) showed that the new statute and the accompanying publicity did not have any tangible effect on the attitudes to drinking and driving. In contrast, a survey study from Norway, where similar but stricter legislation had been in force for forty years, indicated that the law had been successful in reaching the citizens with its message (Hauge). Thus, the two studies taken together give support to the view that the moral effect of the law depends on a longtime process.

Limits of Research

The stream of research papers and the accompanying theoretical discussions have above all clarified the methodological problems and illustrated the limitations of different research methods. The research has produced fragments of knowledge that can be of use to check and supplement commonsense reasoning, which will have to be relied on for a long time to come. There is a long way to go before research can give quantitative forecasts about the effect on crime rates of contemplated changes in the system. Some researchers have tried to quantify their findings. The best-known example is Isaac Ehrlich’s controversial work on the effects of capital punishment on the murder rate. According to Ehrlich, statistics on the use of capital punishment in the United States in the years from 1933 to 1969 indicated that each execution in this period had prevented seven to eight murders. The study has been severely criticized (see Beyleveld), and such quantitative assessments seem clearly premature.

It may be asked how far the problems of deterrence are at all researchable. The long-term moral effects of criminal law and law enforcement are especially hard to isolate and quantify. Some categories of crime are so intimately related to specific social situations that generalizations of a quantitative kind are impossible. One may think of race riots, corruption among politicians and public employees, and many types of white-collar crime. An inescapable fact is that research will always lag behind actual developments. When new forms of crime come into existence, as did hijacking of aircraft or terrorist acts against officers of the law, there cannot possibly be a body of research ready as a basis for the decisions that have to be taken. Common sense and trial and error have to give the answers.

Deterrence and Public Sentiment

Most serious students of crime and criminal justice probably would agree that the fluctuations in crime rates have more to do with social and economic changes than with changes in criminal law. However, the limited role of criminal justice has not become common knowledge. It seems that politicians as well as the general public tend to overestimate the deterrent effect of criminal law on crime rates. Moreover, in the political struggle more votes are won by promising to be tough on crime than by taking a moderate attitude. A complicating factor is that the invocation of deterrence may be a cloak for retributive feelings. This is most obvious with regard to the death penalty. In this field public sentiment in the United States contrasts sharply with that of the rest of the Western world.

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