Vol. 4 No. 9 (September, 1994) pp. 133-135
CRIMINAL INCAPACITATION by William Spelman. New York: Plenum
Press, 1994. 338 pp. Cloth $ 39.50.
Reviewed by Kent E. Portney, Department of Political Science,
Tufts University.
In a policy area that is as charged with emotion as any, debate
about the proper goals of criminal justice and the criminal
sanction is frequently dominated by the uninformed and the
politically expedient. There is little doubt that the idea of
incapacitating criminals has captured the imagination, if not the
pocket books, of the American people and many of their
representatives. Yet it is not beyond the realm to wonder, as
many scholars do, whether prescriptions to focus the criminal
sanction exclusively on incapacitation seek a quick fix, perhaps
carrying high hidden and long-term costs, that in the long run
will prove no more effective in reducing crime than any other
possible reform. In the face of this, Professor William Spelman
from the LBJ School, attempts to provide a rational econometric
analysis of incapacitation to demonstrate that when utility
issues are systematically investigated, pursuing policies of
broad based incapacitation are much more of an economic gamble
than pursuing policies of selective incapacitation, where
specific types of criminal offenders are targeted. Indeed, the
central focus of this book is not on the incapacitative effects
of crime control policies per se, but rather the economic
efficiency of pursuing some kinds of incapacitation-oriented
policies rather than others.
This is not a book for the faint of heart when it comes to
statistics and mathematical modelling. Its overall methodology is
one of identifying the types of data that would be needed to make
predictions or estimates of the crime-reduction effects of
incapacitation, to review the existing empirical literature and
sources of these types of data to establish the range of existing
estimates, to use these estimates to make educated guesses that
can be plugged into models which estimate crime-reduction
effects, and to conduct some sensitivity analyses to investigate
how dependent the crime-reduction estimates are on particular
types of data. For example, starting in Chapter 2, Spelman
addresses the need to estimate the number of offenses that
criminal offenders commit per year, a rather important piece of
information if one is to make estimates of the number of crimes
not committed due to incapacitation. After reviewing existing
data and assessing specific threats to the validity of these
data, Spelman develops a methodology to adjust or weight existing
data to correct for biases. As much as anything else, Chapters 2
through 5, however, describe how much uncertainty there is in
existing estimates of critical characteristics of the criminal
population.
Chapter 3 focuses on the offense rate -- the number of crimes
committed per offender per period of time -- an important factor
in the ultimate computation of a benefit/cost ratio associated
with incapacitation. Chapter 4 examines "the criminal
career," in an effort to estimate the frequency of crimes
offenders commit at different ages. Spelman finds that high and
low rate offenders are less likely to drop out of criminal
activity at any given time than offenders with moderate offense
rates. Chapter 5 focuses on arrest rates -- a factor which
necessarily affects the ability of the criminal justice system to
incapacitate. Spelman finds that as offenders gain experience
committing serious crimes, they learn to avoid being arrested by
police. Police tend to learn to identify experienced offenders,
but their efforts are overwhelmed by the effects if offender
learning.
Starting in Chapter 6, Spelman uses the data estimates derived in
the previous chapters to begin making estimates of the
crime-reduction effects from incapacitation. He distinguishes
between "collective incapacitation," (addressed in
Chapter 6), where the focus is on the crime-control effects, due
to incapacitation, of the present criminal justice system, and
"selective incapacitation," (addressed in Chapter 7),
where the focus is on efforts to increasingly target specific
types of offenders. I might add that nowhere is there a clear
definition of the concept of collective incapacitation as used in
the analysis, although it does have to do with "...the
likely crime-control effects of the present criminal justice
system."(p. 197) The problem with this, of course, is that
the current system incorporates, to varying degrees, efforts to
selectively incapacitate. This raises the question of whether the
implicit description of current practice as pursuing collective
incapacitation has any real meaning.
There is little question that this book represents a significant
contribution to the empirical literature on incapacitation. It is
not, however, without problems. For example, because the effort
is oriented around secondary analysis of existing data from other
sources and studies, there is no consistent data base used
throughout the study. This means that some of the estimates are
based on data from states, where a significant amount of the data
come from California, Michigan, and Texas. Other data come from
studies of cities, especially Philadelphia, Washington, and New
York. In some cases, data are available for a broader array of
states, and no explanation is given for why expanded analysis is
conducted only on a particular handful of them. At one point,
data from a study conducted in London are presented without any
explanation of why this might be pertinent to the analysis of
criminal incapacitation in the U.S.
Perhaps a more difficult issue has to do with the issue of
drug-related crimes. Although Spelman's analysis incorporates
analysis of "drug sales" crimes, it is not at all clear
that the analysis was able to fully capture either the challenge
that drugs have created for the justice system, or the potential
for selectively incapacitating offenders who have committed
crimes where drugs are involved. Most practitioners, casual
observers, and some scholars seem to believe that there has been
something of a fundamental change in the way that drugs influence
criminal activity today, and that this change is of relatively
recent vintage. Initially, this raises the question whether only
very recent data should be used to model crime-reduction effects
of incapacitation. The potential for selective incapacitation may
not have been fully captured in this analysis because it was not
able to distinguish crimes where drugs played some role. A policy
of selective incapacitation could very easily be formulated to
target offenders who commit robbery or burglary where there
appears to be some involvement with drugs, such as crack cocaine.
Spelman's analysis sheds little light on the potential
cost-effectiveness of such targeting. All this is to say that
perhaps selective incapacitation would be even more
cost-effective than Spelman's analysis suggests.
All things considered, Spelman's work represents an impressive
attempt to assemble what is known about incapacitation, extending
that knowledge to make it more generalizable. By assessing the
quality of data relevant to incapacitation, and by addressing the
issues of uncertainties associated with these data, Spelman has
done a service to scholars by providing a clear picture of major
areas where future analysis would be productive. Ultimately, the
analysis should add a note of caution to any policy maker who
sees the indiscriminate pursuit of incapacitation goals as the
answer to the crime problem in the U.S.
Copyright 1994