Incapacitation

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INCAPACITATION

Incapacitation is one of the mechanisms through which prisons contribute to crime prevention. While incarcerated an offender is restrained from committing crimes, at least outside the prison walls, and thus it is said that prisons incapacitate offenders from "additional mischief," as William Blackstone once put it. For at least two hundred years incapacitation has been recognized as one of the legitimate objectives of the criminal law alongside deterrence and retribution, but arguably since the mid-1970s incapacitation may have become the main rationale for imprisonment, certainly in the case of the United States.

Until 1975 the incarceration rate nationwide remained strikingly steady averaging 107 prison inmates per 100,000 residents. Thereafter, and particularly since the early 1980s, the prison population grew at an astonishing rate of 7.2 percent each year, leading to a fourfold increase in the nation's incarceration rate by the end of the century.

The so-called war on drugs was certainly an important factor fueling this colossal expansion of imprisonment. Under this approach, introduced during the first Reagan Administration, stiff criminal sanctions replaced treatment-on-demand as the main weapon of choice to fight the use of illegal substances. The effects of this policy change were dramatic in the extreme. The number of drug inmates increased from just under 24,000 in 1980 to almost 240,000 in 1996. Yet, it would be a mistake to conclude that the shift in imprisonment levels was entirely or even mainly attributable to the change in drug policy. During the period 1980–1996 the number of inmates in prison for a violent offense increased by 248,000 whereas inmates serving time for a property offense grew by almost 150,000 prisoners (Blumstein and Beck). The wave of punitiveness did not materialize equally across states and among crime types, but there is no documented instance of a single jurisdiction or crime domain completely sidestepping the trend toward higher levels of punishment (Cohen and Canela-Cacho).

To an important extent, the increase in incarceration levels was the result of the public's cry for swifter and tougher criminal sanctions simply on grounds of retribution, particularly after the proliferation of victims' rights groups. The late 1970s saw not only the demise of the "rehabilitation ideal"—the use of prisons as a tool for the reformation of offenders—but also the rebirth of the notion of prisons as a place of penance. But to a much larger extent, the unprecedented expansion of incarceration reflected almost a blind faith among a large portion of the population and a dominant segment of elected officials that prisons are an effective means, and sometimes the only means, to prevent serious crimes. True, chronic offenders may be beyond rehabilitation and may be essentially immune to deterrence, but, in the words of the celebrated conservative columnist Ben Wattenberg, "a thug in prison can't shoot your sister."

The enactment since 1993 of so-called three-strikes-and-you're-out statutes in twenty-six states (Zimring et al.) is perhaps the best indicator of the public's confidence that crime can be best prevented through incapacitation. These statutes typically provide for mandatory sentences or life imprisonment for offenders convicted of a serious offense and who also have two or more prior convictions for violent or serious crimes. In some states, such as California, the "third-strike" need not be a conviction for a violent offense. These draconian measures have been largely accepted by the public not only as fair policies but as wise ones, premised on the notion that "three times an offender, always an offender," and that society has a right to permanently incapacitate those who cannot control their criminal urges.

This entry reviews the extant scientific literature on incapacitation, in particular studies that have attempted to measure the crime suppression effects of incapacitation. In a subsequent section, the entry reviews current knowledge on patterns of offending behavior that has a direct bearing on incapacitation policy. In this regard it is of special importance to assess what we know and do not know about offenders that are the prime targets of incapacitation, namely those who engage in frequent criminal doings over a long portion of their lives, and that historically have been called habitual offenders, chronic offenders, career criminals, and, more recently, life-course persistent offenders. The entry closes with a brief discussion of new policy developments, some of which continue the trend toward more incapacitation, while other teens seem to offer a reprieve from the era of punitiveness.

The scholarly literature on incapacitation and the measurement of incapacitative effects

The empirical literature on incapacitation is of recent vintage, going back to the early 1970s. Although arguably the most important rationale for imprisonment these days, incapacitation continues to be the least studied of the prison's functions. For the period 1990–1999, the Criminal Justice Abstracts lists only 85 incapacitation publications, compared to 509 for deterrence and 639 for rehabilitation. This gap in publications was substantially more pronounced in the 1980s, for example one incapacitation article for every fourteen articles on deterrence (Zimring and Hawkins).

The works by Cohen (1977, 1983), Zimring and Hawkins, Nagin, and Spelman (2000b) provide an excellent basis to track the evolution of the incapacitation literature over the past twenty-five years. Together they also give us a good portrait of what we know in the domain of incapacitation and, particularly, how well we know it. One important observation is that from the very beginning, scholars of high standing in the criminal justice academic community have disagreed on the basic point of whether the crime suppression effects of prison-incapacitation are large or small.

The two most important 1970s articles on incapacitation, published in the same issue of the Law and Society Review in 1975, illustrate the point. As reviewed by Cohen (1977), the first of these articles, written by David Greenberg, concluded that the crimes prevented by incapacitation amounted to no more than 8 percent of the total crimes actually committed, and perhaps as little as 1.2 percent. The second article was authored by a father-son team of noncriminologists, the Shinnars, and was one in a series of three articles essentially presenting the same model, which ultimately would have a lasting influence on the incapacitation literature. The Shinnars concluded that in the 1970s crimes prevented through incapacitation amounted to 25 percent of crimes committed, three times higher than the upper-bound effect suggested by Greenberg. Moreover, they argued that just as recently as the 1960s, when the risk of incarceration per crime committed was substantially higher, the number of crimes prevented through incapacitation amounted to 120 percent of crimes committed.

Despite substantial progress in methods and theory, disparities in the estimates of incapacitation put together by the best in the discipline continue to be huge, leading Nagin to conclude that "The evidence [about incapacitation] is of limited value in formulating policy. . . . [Predicting] the timing, duration, and magnitude of the impact of incremental adjustments in enforcement penalties remains largely beyond our reach" (Nagin, p. 367).

To understand why measuring incapacitation is such a difficult enterprise one needs to remember that the essence of this exercise is to count crimes that did not occur. Unavoidably, one needs to engage virtual reality and ask questions of the following two basic types: How many crimes would the 162,000 inmates incarcerated in California during the year 2000 have committed had they been free? Or, between 1996 and 1997 California increased its prison population by 9,200 inmates: What difference did that make, if any, in the actual crimes committed during 1997?

In answering these questions empirical evidence readily available to scholars consists of the crime rate, as reported to the police, and the actual imprisonment rate. At first sight, these two variables should provide all we need to assess incapacitation, for intuitively, the more people imprisoned, the larger the number of crimes prevented, and, all other things being equal, the smaller the crime rate.

Unfortunately, this logic can be seriously flawed for various reasons. To begin with, incapacitation and deterrent effects are commingled, a fact recognized since the first works on incapacitation (Cohen, 1977) and, to this day we lack a proven methodology to separate the two. The two effects are commingled because they both respond in the same direction to increases in imprisonment levels. As the prison population increases more offenders are incapacitated but also other would-be offenders may be deterred from committing additional crimes, in light of the higher incarceration risk. Both effects would lead to a reduction in the crime rate.

Second, all other things are hardly constant when imprisonment policies change. In all likelihood the opposite is the case: criminal sanction policies often change following observable changes in crime rates or in a number of other contextual factors that may have an effect on crime. Consider, for example, a situation in which the robbery rate increases by a factor of two, for reasons having nothing to do with the current level of criminal sanctions. In this case one could see an increase in the observed robbery rate and also very likely an increase in the number of people going to prison for robbery. Arguably, the number of prevented robberies via incapacitation would have increased because more robbers would now be in prison; it would be entirely likely that because of the increase in the robbery rate, the criminal sanctions would be further toughened, but still, one would not see a decline in actual robberies. Incapacitation would be expanding but not fast enough to catch up with the expansion in robbery offending. One can play the opposite scenario and easily identify a situation in which the prison population is going down, the number of crimes prevented by incapacitation is going down, and the observed crime rate is also declining.

The important point to keep in mind is that measures of simple correlation between incarceration rates and crime rates are not sufficient to assess incapacitation effects and may very well be misleading. Figure 1 provides a telling illustration of the ambiguous relationship over time between the incarceration and crime rates using California data for the period 1963–1998.

For robbery and burglary Figure 1 displays the crime and incarceration rates as percents of their respective 1963 values. Thus, Figure 1a shows that between 1963 and 1980 the incarceration rate for robbery remained roughly stable whereas during the same period the robbery rate increased by a factor of four. The correlation of the crime and incarceration rates for robbery over this period would be close to zero, as the first was rising sharply and the second was roughly stable. After 1980 and through 1988 the correlation is negative as the imprisonment rate steadily increased and the crime rate steadily decreased. After 1988 and through 1993 the correlation switches to a positive value with the robbery imprisonment rate continuing its assent at a constant rate relative to the prior period while the robbery rate showed a steep increase. The most striking segment of Figure 1a is the story it reveals after 1992. One observes what can be described as a meltdown of the robbery rate at a time when the imprisonment rate for robbery began to flatten. One can find segments of time in Figure 1a to advance claims that the incapacitation effect is either large or irrelevant or actually counterproductive.

The story for burglary displayed in Figure 1b is very different from that of robbery and almost uniformly supportive of the hypothesis that the incarceration and crime rates move in the opposite direction, as expected under the most simple scenario of how incapacitation works. Together Figures 1a and 1b show that the ambiguity of the relationship between incarceration and crime rates occurs not only over time within crime types but also across crime types. This introduces yet another possibility: that incapacitation works for some crimes but not for others.

Estimates of incapacitation

This section presents incapacitation estimates derived from modeling exercises in which various statistical controls were used to overcome the inherent ambiguity between incarceration and crime rates described before. It has been noted that incapacitation estimates vary enormously by source. However, sometimes the differences in estimates are exaggerated because estimates calculated under different metrics are directly compared.

Historically there have been four conceptually different incapacitation measurement systems. The earlier measures were of the type provided by Greenberg and the Shinnars, previously mentioned. In this approach incapacitation is measured by the percent that crimes prevented represent relative to crimes committed, or some variant of this basic calculation, often referred to as the incapacitation effect. More recent measures of incapacitation focus on the number of crimes prevented per offender in prison, using the average or median offending rate of offenders in prison as the basis for that calculation. A third measure favored by economists measures incapacitation as an elasticity, that is, the percent change in the crime rate following a 1 percent change in the incarceration rate. Finally, a fourth useful measure attempts to measure what could be described as marginal incapacitation, and that is the number of crimes prevented by the incarceration of additional inmates in the event of an expansion in the prison population.

While these four measures are obviously interrelated, numerically they are not equivalent. For example, Levitt provides both elasticity and marginal incapacitation estimates based on the same data and model. The elasticity estimate is fairly small, -.31, suggesting that for a 10 percent increase in incarceration rates the crime rate would be about 3 percent below where it otherwise would have been. To some this would be evidence that incapacitation effects are negligible; yet, the marginal incapacitation estimate that accompanies this elasticity value is 14.9 crimes prevented for each additional inmate joining the prison population, evidence to many of large incapacitation effects.

When comparing incapacitation estimates one needs to make sure that the incapacitation measures in question belong to the same type, otherwise the comparison would be misleading. In this entry the incapacitation estimates discussed below belong to the type previously defined as marginal incapacitation measures (Table 1) or to measures of the elasticity of incapacitation.

The first two sets of estimates presented in Table 1 (Marvell and Moody; Levitt) were obtained using similar methods and data sets. They both rely on a statistical technique called regression analysis to assess changes in the crime rate as a result of changes in the incarceration rate, controlling for other factors that could influence that relationship, such as the demographic composition of the population and levels of economic well being. The data informing these two models spans the period 1971 to the early 1990s and includes all states. The Zimring and Hawkins incapacitation estimates (1995) also rely on the relationship between crime and incarceration rates but in a nonregression estimation context, and are based only on California data covering the period 1981 through 1990. These three sets of estimates are comparable in that they provide marginal incapacitation estimates by crime type and for the aggregation of all crimes, and they are all based on aggregate crime and imprisonment rates.

The last set of estimates in Table 1 are an extrapolation specifically prepared for this entry based on results reported by Canela-Cacho and colleagues. The latter estimates are based on a completely different methodology relying on individual offending rates to calculate incapacitation effects rather than aggregates of crime and incarceration rates. The estimates are based on California data and apply to the same time period considered by Zimring and Hawkins. In addition, the individual offending rates used in this approach derive from surveys of prison inmates where offenders have reported their crimes.

Some commonalities in the four sets of estimates are readily apparent. The marginal incapacitation estimates are all substantially higher for burglary than for robbery, and this applies generally to property crimes vis-à-vis violent crimes. In addition, the size of the estimates for marginal burglary incapacitation is virtually the same in the estimates by Levitt, Zimring and Hawkins, and Canela-Cacho and colleagues.

However, the differences across estimates are striking concerning marginal incapacitation for violent crimes. The Marvell and Moody estimate is 2.5 times that of Zimring and Hawkins, whereas Levitt's estimate is 4.6 times that of Marvell and Moody. For robbery, similar differences exist among the four sets of estimates. These differences raise concerns since the Levitt and Marvell and Moody estimates rely essentially on the same data and apply the same genre of statistical models. The estimates of Zimring and Hawkins and Canela-Cacho and colleagues are based on completely different methodologies but they both apply to California during the same time period, and again, with regard to robbery, the estimates are dramatically different. Perhaps the one conclusion we can reach is that substantial uncertainties remain in the size of incapacitation effects, despite some impressive methodological advances in the measurement of incapacitation.

The crime drop throughout the United States that began in 1992 has given new impetus to the study of incapacitation effects, as scholars are busily trying to explain what contribution imprisonment played, if any, to this large and for the most part unexpected decline. Not surprisingly, in a context where homicide and robbery rates have experienced declines of over 50 percent in seven years, the new rounds of incapacitation estimates tend to be larger than estimates based on data prior to 1992, even when the same methodology is applied. For example, Spelman (2000a) redid Levitt's analysis expanding the data through 1997 and reports an increase in the incapacitation elasticity of 41 percent between 1973 and 1997.

Similarly, some recent work examining the incapacitation effect for homicide reports elasticities of -1.5 to -1.9 (Marvell and Moody, cited in Rosenfeld). Rosenfeld analyzed the decline in homicides in the period 1990–1995 and concluded that the high elasticity estimates just cited are in agreement with his finding, obtained independently, that the homicide rate would have been 28 percent higher absent the incapacitation effect generated by an average annual increase of about 67,000 prison inmates between 1990 and 1995.

It should be noted that the crime types for which incapacitation estimates have been attempted are limited to violent offenses and to some property offenses. No one seriously has entertained the notion that putting one drug dealer behind bars would prevent a number of drug transactions; the incarcerated offender would be easily replaced by someone else in the streets as long as the demand for drugs continues unabated. Such replacement effect is unlikely to apply to offenses like robbery or burglary, except in the context of co-offending where two or more individuals team up to engage in criminal acts. Reiss pointed out that the incarceration of one of the members of a group of two or three offenders acting together need not have an incapacitative effect as the remaining free members of the group could recruit a new member to replace the incarcerated peer.

There are two additional situations that could further negate or at least diminish incapacitation. The first one relates to crime desistence, a phenomenon exhaustively documented in crime research. Simply put, as a result of aging, many offenders stop committing crimes, and thus past a certain point their incarceration yields no incapacitation benefits.

In the second case, incapacitation would initially be effective but would eventually become counterproductive, if as a result of an episode of incarceration, an offender upon release evolves into more serious crimes or engages in the same criminal behaviors but at substantially higher rates. In this instance prisons would have a criminogenic effect, preventing some crimes at first but at the expense of contributing to more serious or to a higher number of crimes in the future.

The incapacitative estimates presented before only indirectly attempt to control for replacement or desistence of offenders following incarceration, and none allow for the possibility that prisons are indeed criminogenic. These omissions further compound the uncertainties surrounding the available incapacitation estimates and show the need to develop yet better measuring techniques and substantially richer data sets.

Offending trajectories and incapacitation policy

One of the most robust findings in criminal justice research is the heterogeneity in offending rates and in deviant behavior generally, across the population. Longitudinal research studies in various countries such as the United States, Canada, England, Denmark, and New Zealand have found that when a group of individuals born the same year (a "birth cohort") are monitored from birth to adulthood a small percentage, typically under 10 percent, account for the majority of crimes generated by the entire cohort. For example, in the now famous study of a birth cohort of Philadelphia boys by Wolfgang and colleagues, 6 percent of boys were responsible for 52 percent of all police contacts generated by the cohort.

In longitudinal cohort studies the vast majority of cohort members do not report any criminal activity when interviewed and do not have an official criminal record. Among those with at least one reported criminal justice contact, 15 to 20 percent often account for about half of the total crimes. Comparable findings have been obtained when analyzing reported offending rates of prison inmates (Chaiken and Chaiken).

The subset of offenders with substantially higher offending rates than the average offender has been the subject of much criminological research, for not only do they represent the natural population in which to study the effect of various factors influencing onset and termination of criminal behavior, but they also constitute a natural target for incapacitation (as well as special deterrence and rehabilitation).

Capitalizing on the existence of high rate offenders, and seeking to achieve large incapacitation levels with low incarceration rates, the controversial policy of selective incapacitation was advanced in the early 1980s by Greenwood and Abrahamse. In the area of incapacitation and even in criminal justice policy generally, few scholarly proposals have generated as much controversy and heated exchanges as the idea of selectively incarcerating offenders based in part on their expected future crimes. Ethical and legal concerns, coupled with the inability to prospectively distinguish with accuracy high and low rate offenders, have precluded the implementation of selective incapacitation policies, even on a trial basis. Instead, what happened was a toughening of criminal sanctions across the board but especially for repeat offenders with multiple prior convictions. For example, the three-strikes-andyou're-out statutes previously discussed impose very long sentences on offenders with two or more prior convictions, presumably because those prior convictions indicate a high criminal propensity. However, the application of this scheme does not call for any predictions of future criminality and treats exactly alike two offenders with the same prior record and the same current offense. Still the foundation of this policy is the existence of chronic offenders whose incapacitation allegedly yields high social returns. It is ironic that to overcome the ethical and legal concerns associated with assigning incarceration terms partly based on unreliable predictions of what an offender may do in the future, we essentially adopted the policy that two prior strikes automatically qualify a convictee as a chronic offender and thus a good target for long incapacitation. Clearly, many false positive predictions result from this policy and apparently its only redeeming grace is that the prediction it implicitly relies on is based on past rather than future behavior.

Since around 1990, much has been learned about high rate offenders as a result of the development of new statistical techniques applied to data sets collected from longitudinal studies. The joining of developmental theories in psychology with the criminal career approach of the 1980s has been particularly fruitful and is a promising source of new policy insights. The criminal career paradigm brought attention to the dimensions of individual offending, namely age of onset of offending, frequency and seriousness of offending, and termination of offending. The approach was particularly helpful in recognizing that crime control policies could differentially affect each of the dimensions of individual offending, and that in turn particular attributes of criminal careers could affect the effectiveness of crime control policies. For example, early on the limits of incapacitation due to of career termination were recognized. Developmental psychology and longitudinal research methods have infused the criminal career paradigm with a theoretical foundation and a much more powerful dynamic outlook. The resulting new approach, often referred to as "criminal trajectory analysis," looks closely at the interaction of personal attributes and external events in the unfolding of an offender's course of criminal acts. The approach is also dynamic in that it seeks to determine how aging affects an individual's trajectory. Important pioneering works in this new tradition are those of Terri Moffitt from the developmental psychology perspective, and of Nagin and Land from the field of quantitative criminology.

The criminal trajectory approach has confirmed that not all offenders have the same propensity to engage in criminal behavior and in deviance generally. Offenders vary in their frequency of deviance involvement as well as in the number of years during which they engage in those behaviors. Typically, these studies find three distinct groups among the members of a cohort with delinquent acts, each with a typical "offending trajectory": adolescent-limited offenders, low-level chronic offenders, and high-level chronic offenders (Nagin et al.; Fergusson et al.). These groups are different in a number of ways, for example the adolescent-limited typically start offending in early adolescence and generally stop offending altogether in early adulthood. In contrast, high-level chronic offenders have their criminal onset during childhood and continue their involvement in crime and deviant behavior for long periods of time. Oftentimes this group consists mostly of children with neuropsychological deficits who have faced disadvantageous social and family environments from day one in their lives.

A very important insight from this new generation of longitudinal studies pertains to the relationship between age and criminal involvement. Even high-level chronic offenders show a declining criminal trajectory after a certain age, contradicting past notions that high-rate offenders maintain a constant rate of offending while criminally active. This insight is important as it makes clear that some incarceration time will have either declining returns or even, possibly, no returns. Beyond a certain point in an offender's incarceration term, he would not commit additional offenses if free, and thus the rationale for incapacitating him is lost.

The new longitudinal studies may eventually provide us with better ways to prospectively identify high-level chronic offenders among all offenders. The development of that ability need not entail the return of proposals of selective incapacitation, and in fact there is presently no literature in print exploring that possibility. Rather, as we learn to precisely identify the set of conditions, from conception to adulthood, that turn an individual into a high-rate chronic offender, society may be moved to intervene early, and not necessarily in a criminal justice context, to undermine the host of conditions pushing individuals into a trajectory of sustained offending.

The future of incapacitation policies

Various policy developments in the 1990s suggest that the era of punitiveness with emphasis on incapacitation will not be over anytime soon. Two instances of policies along these lines are the passage of "sexual predator laws" and the increasing use of the adult criminal system to prosecute and sanction juveniles as young as fourteen years of age.

Washington state passed the first sexual predators statute in 1990 and thereafter nine other states have enacted basically equivalent laws (Lieb et al.). These statutes target incarcerated sex offenders who are soon to be released having completed their sentences. If the offender can be shown to suffer from a "mental abnormality or personality disorder that makes [him] likely to engage in future predatory acts of sexual violence" (Wash. Rev. Code 71.09.020, emphasis added) the statute authorizes the state to confine the just released inmate for treatment until a jury finds him safe for release. Clearly, the objective of the statute is to extend the incapacitation of these inmates past the end of their incarceration sentence, a sort of "incapacitation beyond punishment."

These statutes have been particularly controversial. Disavowing well-established principles of civil commitment law and practice, the sexual predator statutes do not require a showing that the person is "mentally ill" but instead rely on the malleable concept of "mental abnormality or personality disorder." The former term is limited to diagnosable medical conditions such as schizophrenia; the latter does not have a uniform clinical definition. Some also argue that with the sex predator laws the state is able to apply in series, and essentially based on the same facts, two control mechanisms (criminal sanctions first and then civil commitment) that until now were incompatible with each other. The Supreme Court, however, has found these statutes constitutionally acceptable in two recent rulings (Seling v. Young, 121 S.Ct. 727 (2001); Kansas v. Hendricks, 521 U.S. 346 (1997), essentially on the ground that the statutes are not punitive and therefore do not constitute double jeopardy, and under the guise that incapacitation of dangerous sexual violent predators is a legitimate exercise of the states' regulatory power to secure public safety.

Thus far the sexual predator statutes have been applied in a very limited number of cases, by one count under 1 percent of all eligible released inmates (Lieb, 1998), and there is no evidence that the same approach will be extended to other violent predators. Still the precedent has been set for a policy of incapacitation beyond the completion of a criminal sentence.

Another telling indicator of the remaining support for tough criminal justice policy for the sake of crime prevention is the shift of underage perpetrators from the juvenile to the adult system. Of all new admissions into prison nationwide, 2.3 percent were children (as young as fifteen, in New York and North Carolina). Despite the sizable declines in violent crime levels since 1992, the public apparently agrees with the proposition that more gains can be achieved by further toughening criminal sanctions. California approved a referendum, by a two-to-one margin, that requires juveniles fourteen years of age or older charged with murder or a serious sex offense to be tried in adult court.

But there are also some promising policy developments for crime control that are not imprisonment-based. There is an impressive body of scientific evidence showing that drug treatment is a very efficient means for crime control, vastly superior to imprisonment in many contexts. Caulkins and colleagues have shown that the resources consumed by mandatory minimum sentences for drug offenders would have greater social returns—in terms of crime control and in other ways—if they were spent in drug treatment facilities. Along the same lines, a large quasi-experimental study of drug and alcohol treatment in California (Caldata) showed that on average every dollar invested in drug treatment yields the equivalent of $7 in social returns, most of it on account of the reductions in criminal behavior of the persons receiving treatment.

It has often been argued that the incarceration of drug users results in little or no incapacitation of serious crimes. That conventional wisdom may or may not hold true. Some rigorous studies have shown that the criminal records of offenders in prison for a drug offense are comparable, in terms of prior violent or property crimes, to the records of offenders in prison for property of violent offenses (Cohen et al.). But the point that drug users may be good targets for incapacitation does not contradict the notion that these same offenders, or at least a fraction of them, are even better targets for drug treatment.

California again is showing the way, in this case with a bold policy that finally heeds the findings of rigorous research that drug treatment pays off. Beginning on 1 July 2001, offenders convicted of a "nonviolent drug possession offense" are sentenced to probation and are required to complete a drug treatment program. This new system will require that the state create a treatment trust fund of almost $700 million for the first six years of the program. In return, the state expects to save up to $250 million a year in state prison operating costs and a one-time savings of $500 million on capital outlay costs. Of course, the attention will not focus on the financial savings from diverting offenders from prisons to drug treatment facilities. We have always known that the latter are substantially less expensive than the former. The focus will be on what happens to the criminal propensities of the diverted offenders: Will a drug offender in treatment not shoot your sister? Will the incapacitation returns on account of drug treatment surpass the incapacitation returns from imprisonment?

The drug treatment initiative is part of a more general trend in what can be called the cost-benefit analysis of imprisonment. Throughout the 1980s and most of the 1990s, scholars probing into the cost-efficiency of prisons posed the question simply in terms of incarcerate or not incarcerate (DiIulio and Piehl; Piehl and DiIulio). Whether prisons pay, in the sense that the benefits of incarceration exceed its costs, is by no means a settled matter (see Spelman, 2000b), but the interesting point is that presently the cost-benefit analysis of incarceration has been expanded beyond its traditional formulation. Greenwood and colleagues (1998) pulled together the best literature on the effectiveness of early interventions in the lives of children at risk of deviant behavior. While we are still awaiting large demonstration programs, the cumulative knowledge acquired to date is suggestive of the notion that, from the standpoint of incapacitating future crimes, an ounce of early intervention is worth a couple pounds of later incarceration. Perhaps the times are ripe to give that policy a real chance.

JosÉ A. Canelo-Cacho

See also Deterrence; Prediction of Crime and Recidivism; Probation and Parole: History, Goals, and Decision-Making; Punishment; Rehabilitation; Retributivism; Sentencing: Alternatives; Sentencing: Disparity; Sentencing: Guidelines; Sentencing: Mandatory and Mandatory Minimum Sentences.

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