Assessing Consistency
and Fairness in Sentencing:
A Comparative Study in Three States

nnnn States with Sentencing Guidelines Systems



Assessing Consistency and Fairness in Sentencing:
A Comparative Study in Three States

Authors:

National Center for State Courts
Brian J. Ostrom
Charles W. Ostrom
Roger A. Hanson
Matthew Kleiman

Information design:
VisualResearch, Inc.
Neal B. Kauder

Production of this report was funded by the
Public Safety Performance Project of the Pew
Charitable Trust’s Center on the States.
Launched in 2006, the Public Safety Performance Project
seeks to help states advance fiscally sound, data-driven
policies and practices in sentencing and corrections that
protect public safety, hold offenders accountable, and
control corrections costs.
The Pew Charitable Trusts applies the power of
knowledge to solve today’s most challenging problems.

Design and layout:

Pew’s Center on the States identifies and advances
effective policy approaches to critical issues facing states.

Michael A. Zanconato

www.pewcenteronthestates.org

Mazmedia

This report summarizes material from a larger study
produced with support from the National Institute of Justice
(2003-IJ-CX-1015). The authors gratefully acknowledge
the generous support of NIJ and the encouragement of
Linda Truitt, our project monitor.

The mission of the National
Center for State Courts is to
improve the administration
of justice through leadership
and service to state courts
and courts around the world.

i



Assessing Consistency
and Fairness in Sentencing:
A Comparative Study in Three States
Criminal sentencing in the American states has undergone
substantial changes during the past several decades.
A major policy shift affecting many offenders is the
introduction of structured sentencing. Policies popularly
known as three strikes, truth-in-sentencing, and
mandatory minimum imprisonment have taken hold
in some states, but a more widespread, substantial
legal policy is the introduction of sentencing guidelines
in at least 20 states and the District of Columbia.
Sentencing guidelines are a relatively new reform effort
to encourage judges to take specific legally relevant
elements into account in a fair and consistent way
when deciding whether a convicted offender should
be imprisoned, and if so, for what length of time.
A common concern of state policymakers for limiting
sentencing disparity under indeterminate sentencing
laws is a fundamental rationale for the adoption of
guidelines. For this reason, most states make explicit
reference in their statement of purpose to achieving the
goals of consistency (predictability and proportionality)
and fairness (non-discrimination) in sentencing.
Exploring how well alternative guideline systems realize
these twin goals is the aim of the current research.

Guidelines consist of two main parts
(1) 	 A specified set of elements to be considered,
such as the formal nature of the conviction offense
and the offender’s past criminal history.

Because both the elements and the corresponding
mechanics of how they are to be applied in individual
cases are highly differentiated and nuanced, guideline
systems vary considerably from state to state.
Comparisons among guidelines are often couched in the
language of one system being more or less “mandatory”
or “voluntary” than another. For example, stricter
departure policies, tighter sentencing ranges, and more
vigorous appellate review are aspects of what are
usually called more mandatory, in the sense of being
presumptive, systems.
In contrast, under a voluntary (or advisory) guideline
system, judges are not required to follow a particular
sentencing recommendation, but must usually provide
a reason when the recommendation is not followed.
Implicit in a preference for more mandatory versus
more voluntary guidelines, is a judgment on the degree
to which judicial discretion must be constrained to best
achieve consistency and fairness.

Key policy questions
(1) 	 Have states designed sentencing guidelines that
achieve a high level of predictability without denying
judges adequate discretion in each individual case?
(2)	 Are there important similarities or differences
in sentencing patterns among states with different
guideline structures and organization?
(3)	 What lessons can be drawn from the experiences
in Minnesota, Michigan and Virginia for other
states around the country?

(2) 	Instructions on how the elements are to be weighted
or scored in terms of their gravity.

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Assessing Consistency and Fairness in Sentencing:
A Comparative Study in Three States

Executive Summary
The National Center for State Courts conducted an
in-depth examination of sentencing patterns in three
states with substantially different guidelines systems:
Minnesota, which has a relatively strict system;
Michigan, whose guidelines offer more judicial discretion, and
Virginia, where compliance with the recommended
sentences is completely voluntary.
Ultimately, how one interprets the observed differences
in outcomes among the three states will reflect individual
views on the appropriate level of judicial discretion.
At the conceptual level, desired consistency in sentencing
outcomes clashes with desirable judicial discretion because
they involve quite different fundamental assumptions.
On the one hand, consistency posits that the most
relevant criteria for classifying cases are identifiable and
applicable to all cases. On the other hand, discretion posits
that cases are sufficiently different to make it nearly
impossible to establish a common means of comparison
in each individual case. This study accepts the creative
tension between consistency and discretion, which
seems reasonable given the current state of knowledge,
and therefore makes no attempt to rank the overall
effectiveness of the three systems.
Because all guideline systems reflect alternative choices
about the appropriate level of judicial discretion, the
study identifies six criteria that define and distinguish
sentencing guideline systems in the United States.

2

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Based on the how each state to these criteria, the study
places all of the existing guideline systems along a
continuum from more voluntary to more mandatory.
From this perspective, it is possible to assess the degree
to which three important sentencing goals — predictability,
proportionality, elimination of discrimination — are
realized in the context of sentencing systems at various
points on the sentencing continuum. This study selected
the three states of Minnesota, Michigan and Virginia
because they fall at different points along the continuum.

Key Findings for Policymakers
(1)	 Guidelines make sentences more predictable.
Guidelines substantially achieve their goal of steering
courts toward certain sentences for certain types of
offenses and offenders. They result in greater consistency
in deciding who goes to prison and for how long.
Guidelines also produce differentiated punishment:
like cases are treated alike while unlike cases result in
different degrees of punishment severity. These findings
stand in marked contrast to the inconsistent and
discriminatory sentencing practices documented in all
three states prior to the implementation of guidelines.
More narrow sentence ranges lead to slightly more
predictable sentences. Predictability is somewhat higher
in Minnesota, where the more mandatory system uses
a compact set of sentencing criteria and has relatively
narrow sentencing ranges. In contrast, Virginia’s
voluntary system is based on detailed calculation of
sentences but its wider ranges build in more opportunities
for the exercise of discretion. Consequently, relatively
lower predictability is expected, and found, in Virginia.

(2)	 Guidelines effectively limit undesirable sentencing disparity.

(4)	 State officials have options when designing guidelines.

Guidelines reduce disparities due to factors that should
not play a role in sentencing decisions. The undesirable
influence of offender characteristics such as race and
economic status were of negligible impact in all three
states studied.

All guideline systems reflect choices on multiple
design considerations about how best to shape judicial
discretion. One contribution of the study is the
identification of a coherent way to view the similarities
and differences in design choices among the many
different state systems. The assessment places state
guideline systems along a single voluntary to mandatory continuum. This scale allows policymakers to
evaluate where their states fit in and to look at other
state experiences in tailoring guidelines to match their
needs and circumstances.

The discretion afforded judges under more voluntary
guidelines does not result in discriminatory sentences.
Drawing on the Virginia experience, there is no
suggestion in the results of a direct trade-off between
predictability and proportionality on one hand and
increased discrimination on the other. A voluntary
guideline system with substantial sentencing ranges
does not necessarily lead to increases in discrimination,
as many observers might have expected.
(3)	 Guidelines make sentencing patterns more transparent.
A valuable by-product of guidelines is that the extent to
which they might fall short in achieving predictability,
proportionality and non-discrimination is observable
and hence correctable through appropriate refinements
to the guidelines. There are specific ways that Michigan,
Minnesota, and Virginia might improve their guideline
policies in terms of redefining their basic guideline
elements as well as monitoring sentencing outcomes
in their respective jurisdictions. Recommendations
for these enhancements are available in a lengthier,
companion publication.

(5)	 Active participation by a Sentencing Commission
is an essential element of effective guidelines.
Established policies are no more self-sustaining over
time than they are self-executing at inception.
Sentencing Commissions play a vital role in quality
control. They are able to discern if sentences are
harmonious with intended goals and make targeted
adjustments when necessary. Given the initial purposeful
and deliberative investment made by policymakers and
commissions to guide sentencing, it is worthwhile to
reexamine basic decision-making elements to solidify
past and current gains as well as reorient future
resources in the most effective manner. Some of the
challenges facing the Michigan system might have
been avoided through closer monitoring.

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Assessing Consistency and Fairness in Sentencing:
A Comparative Study in Three States

Looking Ahead

What is the focus of the current research?

The evidence and experiences gathered in this
examination of sentencing through guidelines should
help inform other states considering the introduction
of structured sentencing or revisions to existing
guidelines. For example, there are critical design
considerations and trade-offs related to the appropriate
breadth of guideline ranges and the simplicity or
complexity of factors used to score convicted offenders.

A critical issue is whether the actual sentencing decisions
under a guideline framework conform to intended policy
objectives. Despite the fact that criminal sentencing has
been a perennial topic of analysis and reform for the past
several decades, little is known about the character of
sentences under guideline systems. In response, the National
Center for State Courts has examined and classified all
states with sentencing guidelines along a voluntarymandatory continuum and selected three state systems as
representative of alternative ways of configuring the control
of judicial discretion (Michigan, Minnesota and Virginia).

States continue to examine how best to address the new
procedural requirements introduced in the US Supreme
Court’s Blakely v. Washington (2004) and United States
v. Booker (2005) decisions. Minnesota’s sentencing
commission has responded to the upward-departure
problem identified in Blakely by increasing the size of
the recommended sentencing ranges. Wider sentencing
ranges within the grid cells should significantly lower
judicial departure rates, a strategy geared toward making
the guidelines “Blakely-proof.” A possible unintended
consequence is that Minnesota will forfeit a very high
degree of predictability — and perhaps proportionality
— in this effort to satisfy the strictures of Blakely.
The results of this study provide policymakers with clear
and persuasive empirical evidence of consequences
that might follow changes in the guideline structure.
While sentencing guidelines obviously cannot solve every
problem and challenge in sentencing and corrections,
the study does offer greater clarity on the essential issue
of how conscious policy decisions intended to guide
judicial discretion affect sentencing outcomes. Future
inquiry should explore how alternative sentencing
guideline regimes affect the ability of states to effectively
manage prison population and control associated costs.

4



Examining the practices in three states,
the research asks three questions:
(1)	 Are actual sentences predictable using the prescribed
elements and mechanics of guideline systems?
(2)	 Do more serious offenders receive proportionally greater
punishment as prescribed by guidelines?
(3)	 Are sentences under the aegis of guidelines fair in the
sense of being non-discriminatory, thereby minimizing
the effects of extra-legal elements, such as the age,
race, gender and geographic location of offenders?
The NCSC develops and applies statistical models designed
to simulate the judicial decision-making process by incorporating the information each guideline system provides a
judge at the time of sentencing. The models, which consist
of statistical equations, are formal representations of the
sentencing process. They are tools to estimate and compare
what sorts of sentences are predicted (or should be expected
to occur) by applying them to information on actual
offenders. The models also make it possible to determine
whether actual sentences achieve proportionality of
punishment along the lines conceived by the guidelines.
Finally, the models enable us to address directly the extent
to which sentences under these three alternative guideline
systems are fair and free from discrimination. Specifically,
viewing guidelines in comparative perspective provides
insight into understanding how more mandatory guideline
systems differ from more voluntary guideline systems.

How do state guideline systems compare?
Drawing on US Supreme Court Associate Justice Louis
Brandeis’s famous insight, guideline states are “natural
laboratories” where sentencing guideline developers
have made different policy decisions on their design
and operation. The end result has been the creation of
sentencing guidelines that take many different forms,
despite broad similarities in their intended purpose.
Acknowledging the variation that exists among the
21 guideline systems, a coherent way to view them
is by comparing them along a common continuum
ranging from primarily voluntary recommendations
to more mandatory provisions on how judges are to
determine appropriate sentences. A direct comparison
of states along this continuum makes it possible
to examine the impact of alternative design options.

A continuum is created by assigning points
to each state based on answers to six questions
concerning the state guideline’s basic organizational aspects and structural features:
Question 1:	
Question 2:	

Is there an enforceable rule
related to guideline use?
Is completion of guideline
worksheets required?

Question 3:	

Does a sentencing commission
monitor compliance?

Question 4:	

Are substantial and compelling
reasons required for departures?

Question 5:	

Are written or recorded reasons
required for departures?

Question 6:	

Is appellate review allowed?

For each question, a state is awarded 0 points for a “no or
unlikely” position, 1 point for a “possible or moderate”
position, and 2 points for a “yes or likely” position.

Continuum Points Awarded
(by Position)
Position
“No or unlikely”
“Possible or moderate”
“Yes or likely”

Points
0
1
2

Summing the points determines the degree to which a
state is mandatory or voluntary. States having higher
total scores based on all six questions are more mandatory than those with lower scores. The following
diagram arrays the states on a single continuum with
one pole emphasizing highly voluntary systems (total
of one point) and the other pole emphasizing highly
mandatory guidelines (total of 12 points).

A Continuum of State Sentencing
Guideline Systems
DE
AL
UT AK
OH
DC
MA
WI MO TN AR LA
MD
1

2

3

4

fl More Voluntary

5

6

7

OR
KS
PA WA
8

9

NC

10 11 12

More Mandatory ‡

Some states have put in place more mandatory guidelines
that more tightly control judicial discretion by using close
monitoring, requiring reasons for departures from
recommended sentences, and allowing vigorous appellate
review. Other states have more voluntary systems where
compliance is not monitored, judges are free to depart
without having to justify their reasons, and appellate
review of guideline sentences is prohibited by statute.

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Assessing Consistency and Fairness in Sentencing:
A Comparative Study in Three States

Continuum Questions Applied to Three States: Minnesota, Michigan and Virginia

6



Enforceable
Rule Related to
Guidelines Use?

Worksheet
Completion
Required?

Sentencing
Commission
Monitors
Guideline
Compliance?

Substantial &
Compelling
Reasons Required
for Departure?

Written or
Recorded
Reasons for
Departure
Required?

Appellate
Review
Allowed?

The Guidelines
promulgated by
the Sentencing
Commission
shall establish
a “presumptive,
fixed sentence
for offenders….”

Requires
completion
of guideline
worksheets.

The Commission
issues an
annual report
of guidelines
compliance.

Judges are
required to give
the sentence
within the
presumptive
range. Judges
can depart from
the presumptive
sentence if “there
exist identifiable,
substantial,
and compelling
circumstances….”

The judge “must
disclose in writing
or on the record
the particular
substantial
and compelling
circumstances….”

Yes.

The Michigan
guidelines state
that, “the minimum
sentence imposed
by a court of this
state…shall be
within the appropriate sentence
range under the
version of those
guidelines in
effect on the
date the crime
was committed.

Requires
completion
of guideline
worksheets.

No monitoring
of guideline
compliance;
sentencing
commission
abolished in
2000.

Judges can
“depart from
the appropriate
sentence range
established under
the sentencing
guidelines…
if the court
has a substantial
and compelling
reason for the
departure….”

Reasons for
departure
must be stated
on the record.

Yes.

The Virginia Code
specifically states
that the guidelines
are discretionary.

While compliance
with guideline
recommendations
is voluntary,
completion
of guideline
worksheets
is mandatory.
Judges are required
to review the
guidelines in all
cases covered by
the guidelines and
sign the worksheet.

The Commission
issues an
annual report
of guidelines
compliance.

Judges are to
be given the
appropriate
sentencing
guideline
worksheets and
should “review
and consider
the suitability
of the applicable
discretionary
sentencing
guidelines…”

In a felony case, if
the court “imposes
a sentence which
is either greater
or less than that
indicated by the
discretionary
sentencing
guidelines, the
court shall file with
the record of the
case a written
explanation of
such departure.”

No.

Why were Michigan, Minnesota
and Virginia chosen for the study?
All sentencing guidelines provide a framework for
assessing the severity of criminal activity and a means
to arrive at a recommended sentencing range. State
guideline systems carry varying levels of authority that
circumscribe the discretion of the judge in determining the
appropriate sentence. A central issue, then, is how to
construct the limits on that discretion and to what end.
To address this issue, three states are selected as representatives of alternative ways of configuring the control of
judicial discretion: Minnesota, Michigan, and Virginia.
Minnesota is the most mandatory system, followed by
Michigan; Virginia is the least mandatory of the three.
Minnesota, for example, tends to have tighter ranges on
recommended sentences for similarly situated offenders
compared to Michigan and Virginia. In addition, Virginia
employs a list-style scoring system to determine appropriate
offender punishment in contrast to the use of sentencing
grids in Minnesota and Michigan. Virginia has one of the
most active sentencing commissions, although it is a more
voluntary system in terms of requiring compliance,
than most states.

What are the critical elements of
the sentencing guideline systems in
Michigan, Minnesota and Virginia?
The design and operation of the three selected guideline
systems are important to describe because their mechanics
are incorporated into a statistical model for analysis
purposes. Additionally, understanding how the guidelines
work in practice is central to examining issues of
predictability, proportionality, and fairness.
The mechanics of guidelines involve detailed considerations and calculations, such as how key information
on offense seriousness and prior record is handled,
how sentences are determined, how sentencing ranges
are established, requirements for departures from
recommended sentences, whether appellate review
is permitted, and how time served is considered.

On the most general level, similarities and differences
among the three sets of guidelines are as follows:
Offender Classification
A starting point for the developers of all sentencing
guideline systems is how to take into account the
interrelationships among:
(1)	 The selection of crime types or crime classifications
for inclusion in the guidelines.
The Michigan grid system distinguishes 9 crime
classifications based on statutory severity, the
Minnesota grid focuses on 11 offense groups, and
Virginia employs worksheets for 15 offense groups.
(2)	 The measurement of prior record.
Michigan (seven measures) and Minnesota (four
measures) use a uniform set of indicators to assess
prior record in all cases for all offense categories.
Virginia has identified 10 possible prior record variables, but the precise selection, number and
scoring varies by offense group.

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Assessing Consistency and Fairness in Sentencing:
A Comparative Study in Three States

Structural Comparison of Minnesota, Michigan,
and Virginia Sentencing Guidelines Systems

Commission Status
Guidelines Format
Number of Grid "Cells"
Sentencing Range Around Guideline Recommendation
Required Time Served
Aggravated Departures From Recommended Prison Range
Mitigated Departures From Recommended Prison Range
Year of Sentencing Data Analyzed

Active
Single Grid System
77
10-15%
67%
29.6%
9%
2002

(3)	 The specifics of the instant offense and is the area where
the greatest differences exist between the three systems.
The Michigan guidelines evaluate each offender on
up to 20 offense variables, including aggravated use
of a weapon, physical and psychological injury to
the victim, the intent to kill or to injure, multiple
victims, and victim vulnerability among others.
Minnesota incorporates specific offense conduct into
the presumptive sentence by imposing mandatory
minimum sentences for selected cases involving
weapons or second/ subsequent offenses. In Virginia,
each offense group has a set of offense conduct
variables that apply specifically to that offense (e.g.,
for Burglary/Dwelling there are six possible aspects
of the offense singled out for scoring, such as dwelling
occupied, crime occurred at night, intent to use a
deadly weapon during the burglary). In addition,
there are selected elements of the offense (e.g.,
weapon type, mandatory firearm conviction)
that may apply across many offense groups.

8

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Abolished
9 Grid System
258
50-67%
100%
4%
1.9%
2004

Very Active
15 Worksheets with Scored Factors
No cells
60-66%
85%
9.4%
9.4%
2002

Format
Minnesota and Michigan use a grid system that places
offenders into specific cells; Virginia scores each individual
offender across a range of variables in a worksheet format.

Recommended Ranges for Prison Terms
Michigan and Virginia have wide ranges and base them
on past judicial practices. In contrast, Minnesota has
narrow ranges based on policy prescriptions concerning
what is appropriate and desirable from the point of
view of controlling correctional resources.

Permissible Departures from Recommended Ranges
Virginia allows judges to impose sentences that depart
from recommended ranges by providing stated reasons,
although the sentences are not subject to appellate
court review. In Minnesota, judges may depart by
disclosing reasons for such action, but the decisions
may be reviewed by the Minnesota Court of Appeals.
Michigan is similar to Minnesota.

Time Served
In Minnesota, offenders generally serve two thirds of
their imposed sentence; in Virginia they serve at least 85
percent. In Michigan, the Parole Board determines the
sentence between the judicially imposed minimum,
which is served in its entirety (100 percent) and the
statutory maximum.
Sentencing guidelines bring together characteristics of
the offense and offender in a designed and structured
format that weighs or scores an offender and then
produces a recommended sentence based on that score.
A primary rationale for the choice and weighting of
selected factors is to create greater predictability and
proportionality and to minimize discrimination in the
sentencing process. To date, the relative success of
alternative sentencing guideline designs in meeting
these fundamental goals remains unresolved.

Why are predictability, proportionality
and non-discrimination important when
assessing sentencing systems?
Based on organizational structure and process, differences
among the three selected state guideline systems are
plausibly linked to different sentencing outcomes. Greater
understanding of sentencing under guidelines begins with
refining the basic vocabulary that describes the characteristics of a desirable sentencing outcome and, by exclusion,
a delineation of undesirable outcomes. Clarifying the
definition of an acceptable sentence provides a solid base to
identify more precisely what are unacceptable deviations.
Consistency, for the purposes of this study, focuses on the
twin characteristics of predictability and proportionality
while fairness focuses on the absence of discrimination.

Predictability in sentencing under guidelines
is comprised of two distinct elements.
(1)	 Sentences are predictable to the extent similar
offenders receive similar sentences.
(2)	 Sentences are predictable to the degree individual
offenders are placed into distinctive groups, each
with a range of justified punishment based on a
“legitimate” set of characteristics.

Sentences should also be proportional; that is,
dissimilar offenders receive dissimilar sentences in
proportion to their degree of dissimilarity.
Under guidelines, the goal is to make sure more
blameworthy crimes receive more severe punishments.
A primary task of sentencing guideline designers is to
make concepts like “similarly situated,” “range of
justified punishment,” and “more blameworthy” precise
and measurable. For example, a given combination of
offense seriousness and prior record on the Minnesota
guideline grid locates and defines a set of offenders
deemed to be similarly situated. Being in the same grid
cell carries the implicit prediction that the offenders
are of comparable blameworthiness and hence should
receive similar penalties.



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Assessing Consistency and Fairness in Sentencing:
A Comparative Study in Three States

Likewise, successive steps up or down the offense
seriousness and prior record scales identify dissimilar
offenders as well as the extent to which they are
dissimilar. In Minnesota, for example, if two offenders
are convicted of the same offense, the offender with a
higher level of prior record score will be recommended
for a more serious sentence. Guidelines define a series
of thresholds that represent jumps from one level of
blameworthiness to another. Because crossing a
threshold carries an increase in the severity of penalty,
it is important that adjacent levels should be formally
and meaningfully distinct from one another. If not,
proportionality is violated.
On the most general level, discrimination refers to
sentences that are different, with the source of the
difference tied to specific extra-legal characteristics of
the defendants. For this reason, the current research
focuses on the kinds of undesirable disparities guidelines
are designed to prevent — those resulting from the
offender’s race, age, gender, the region of the state
in which an offender is sentenced (the key question
with regional variation is whether there are distinct
sentencing “regimes” operating under the banner of
a single sentencing guidelines structure), and the
manner of disposition. Minimizing the effects of
these sources of potential discrimination is an explicit
goal in all three systems examined.

In summary, three criteria related to predictability,
proportionality, and discrimination guide the current
evaluation of whether more voluntary guidelines
perform differently than more presumptive ones.
(1)	 Do similarly situated offenders as defined
by the guidelines receive similar sentences?
(2)	 Do the guidelines provide meaningful and
proportional distinctions between more serious and less
serious offenders?
(3)	 Is there evidence of discrimination in sentencing?

10



What methodology was used to evaluate
consistency, proportionality, and
discrimination in sentencing?
From a research perspective, the legal policy
outcomes (or dependent variables in statistical
models) to be explained correspond to the
following two types of sentencing decisions:
(1)	 Who is sentenced to prison?
The decision is whether to punish a defendant
convicted of a felony offense with a prison sentence
or to impose a less severe penalty, typically involving
some combination of jail, probation, fines, work
release, therapeutic treatment, and restitution.
The choice between these alternatives is commonly known as the “in/out” decision.
(2)	 What determines the length of time
an offender is sentenced to prison?
Aptly characterized as the prison length decision,
the analysis focuses on identifying the factors
influential in determining sentence duration.

A broad range of factors related to offense and
offender characteristics (the independent variables
in statistical models) are included to determine
how they affect sentencing outcomes:
Essential elements and mechanics
of each guideline system
These variables are tailored to fit the unique features of
each guideline system and generally include measures
of the offense at conviction, prior criminal history,
specific conduct surrounding the offense, the type of
grid (Michigan and Minnesota) or guidelines score
(Virginia), the offender’s habitual offender (Michigan)
or modifier (Minnesota) status, and any guidelines
departure (if applicable) from the recommended range.

Extra-legal factors

Proportionality Tests

This set of variables includes measures on an offender’s
age, race, gender, and geographic region of the state.
Statistical models were constructed to estimate
(or predict) the two sentencing decisions (i.e., whether
sentenced to prison and if so, for how long) for each
offender in each state based on information on offenders’
characteristics and the elements and mechanics of each
system. Estimates can be made whether the information
and guideline elements call for imprisonment and
if so, for how long for every individual offender.
The information on offenders was drawn from a large
number of cases in each state; Michigan (N=32,754),
Minnesota (N=12,978) and Virginia (Assault N= 1,614;
Burglary N=1,668). A comparison of the actual sentencing
decisions to the predicted decisions when the statistical
models are applied to information on offenders convicted
of felony offenses reveals how successful the sentencing
guidelines are in terms of achieving predictability,
proportionality and non-discrimination.

The focus here is whether the individual guideline
elements related to offense severity and prior record have
a proportional impact on sentencing. For example, there
are six levels of offense seriousness in the Michigan
guidelines: Is the impact of each level distinct — in a
statistical sense — from the adjacent levels? A movement
between levels carries direct consequences for convicted
offenders in terms of exposure to prison time. Because
guideline designers elected to make these distinctions,
whether the individual intended differences in sentencing
outcomes correspond to actual judicial choice is an
empirical question. Therefore, it is anticipated that more
serious classifications of offense and prior record will
be associated with higher estimated probabilities of
receiving a prison sentence and longer prison sentences.

Predictability Tests
The specific criteria used by the guideline designers
to define the concept of similarly situated are used to
evaluate the internal workings of each guideline system.
The analysis examines whether sentence outcomes
follow in a predictable manner from the combination of
offense and offender characteristics built into the
guideline system. Are offenders sentenced on the basis
of the set of elements provided for in the guidelines?
In statistical terms, do the sentencing guideline factors
account for the observed variation on sentencing?

Discrimination Tests
By examining the statistical coefficients associated with the
impact of each of the extra-guideline variables, the extent
to which a system minimizes discrimination in sentencing
is discernible in measurement terms. The potential
influence of age, gender, race and their interactions with
each other (e.g., young, black men) and other variables
(e.g., state geographic regions) are examined in considerable detail to determine if guidelines are sufficiently
successful in promoting predictability and proportionality
to the point that discrimination is minimized.

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Assessing Consistency and Fairness in Sentencing:
A Comparative Study in Three States

What did the study reveal?
Predictability
Do actual sentences correspond to sentences suggested
by guideline criteria and mechanics? The evidence
indicates a close overall fit between predictions based on
the guideline elements and reality. A model of the In/Out
decision in Michigan predicts 89.9 percent of the cases
correctly; the Minnesota model predicts 87 percent of
the cases correctly; and the Virginia model correctly
predicts 75 percent of Assault offenses and 81 percent
of burglary offenses. Hence, despite differences among
Michigan, Minnesota, and Virginia in guideline design
and structure, the three sets of guidelines work effectively to guide judges in a predictable manner in
making the basic in/out decision.
Predictability also refers to how well an offender’s
placement on the guideline grid (or worksheet score in
Virginia) relates to the actual length of prison sentence
received. Looking at the full range of prison sentences
received by convicted offenders in a particular state

shows a great deal of variation from relatively short,
say 1 year, to very long, say, 50 years. If the guidelines
are operating as envisioned, most of the variation in
sentence length should be related to differences in the
specific offense and offender characteristics scored as
part of the guideline calculation. A key question, then,
is what proportion of variance in observed sentence
length is explained by the guideline factors?
For Minnesota, the statistical model accounts for 86
percent of the variation in sentence length followed
by Michigan (67 percent) and Virginia (53 percent
for Assault and 49 percent for Burglary offenders).
While the proportion of explained variation is related
to where the system is on the voluntary/mandatory
dimension, the predictability in sentence length is
substantial in all three guideline systems. Taking
both the in/out and sentence length decisions together,
all three guidelines have dramatically enhanced the
predictability of sentencing.

Percent of Actual Sentencing Decisions Correctly Predicted by Sentencing Guidelines Models
Prison In/Out Decisions

Sentence Length Decisions

87.0%

86.1%

89.9%

67.2%
75.3%

81.4%

12

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Assault

Assault

Burglary

Burglary

55.4%
49.3%

Proportionality
A second key aspect of consistency under guidelines is
that similarly situated offenders receive similar sentences. Conversely, dissimilar offenders should be
treated differently. Proportionality is a value that
functions as a principle in determining what “different”
means. Simply stated, proportionality entails a balance
between the severity of the offense and prior record
and the degree of punishment.
While the full report examines a series of refined tests
of the degree to which proportionality exists, a look at
two types of tests in the context of the in/out decision
provides insight into the issue. The first test asks: is
there a statistically significant difference between the
likelihood of offenders being sentenced to prison who
are in different locations on the Minnesota and Michigan sentencing grids? For example, do judges make
significant distinctions between adjacent prior record
levels in the Michigan guidelines when imposing
sentences? If so, this information indicates the formal
levels built into the guidelines are efficacious in
drawing distinctions between similar and dissimilar
offenders. Such analysis helps address whether judges
in their actual sentencing decisions employ proportionality when making a horizontal or vertical move
between grid cells.
Policymakers institutionalize jumps in the recommended
severity of punishment following changes in discrete
offense or prior record thresholds. Examining the
column labeled “Percent change in probability of going
to prison” on the table above shows how an increase in
the seriousness of prior record or the seriousness of the
offense changes the estimated probability of receiving
a prison sentence and whether the change is statistically significant.

Assessing Proportionality in Michigan
and Minnesota (Seriousness level increases
from low to high for each variable listed)
Michigan
In/Out Decision

Percent
change in
probability
of going
to prison

Variable

Level

Prior Record
(comparing
% change
from Level A)

Level B
Level C
Level D
Level E
Level F

-2%
2%
12%
28%
38%

Offense
Seriousness
(comparing
% change
from Level I)

Level II
Level III
Level IV
Level V
Level VI

2%
8%
10%
13%
16%

Points/
Level

Percent
change in
probability
of going
to prison

Minnesota
In/Out Decision
Variable
Criminal
History
(comparing
% change
from 0 points)

1 Point
2 Points
3 Points
4 Points
5 Points
6 Points

15%
32%
36%
45%
53%
67%

Severity of
Conviction
Offense
(comparing
% change
from Level II)

Level I
Level III
Level IV
Level V
Level VI
Level VII
Level VIII
Level IX
Level X
Level XI

3%
3%
6%
10%
29%
67%
53%
84%
84%
84%

Note: All changes in probability of going to prison
were statistically significant except for the change from
Level I to Level II for Minnesota Severity of Conviction Offense.



13

Assessing Consistency and Fairness in Sentencing:
A Comparative Study in Three States

The probabilities can be interpreted as
the change in likelihood of going to
prison for offenders found to be more
serious than a lower level baseline
offender. For example, in Minnesota,
the baseline offender is an individual
with 0 criminal history points. An
offender who is similar in all respects
to the baseline offender except with a
criminal history score of 4 points has
a 45 percent increase in the likelihood
of receiving a prison sentence.
Hence, a change in probability should
increase with an increase in the level
of seriousness. More serious offenders,
as measured by more extensive prior
record or more serious conviction offense,
should have a higher probability of
prison. Indeed, this is what is found.
Almost all distinctions are statistically
significant (the exception is no
statistical difference between offense
severity Levels I and II in Minnesota)
and in the right direction (the exception
is that prior record level B in Michigan
is found to be statistically significant
in the opposite direction expected).
Consequently, the guidelines demonstrate effectiveness in distinguishing
more serious from less serious offenders
and in leading judges to sentence
offenders accordingly.

Estimated Probability of Prison
Worksheet A Point Total
Virginia (Assault)
100%
75%

In/Out Threshold (6)
50%

Estimated Probability
Actual Percentage

25%
0%
1

5



13
17
Worksheet A Point Total

21

25

29

Estimated Probability of Prison
Worksheet A Point Total
Virginia (Burglary)
100%

In/Out Threshold (14)
75%
50%

Estimated Probability
Actual Percentage

25%
0%
1

5

The Virginia guidelines are used to
illustrate a second approach to assessing
proportionality. Whether the guidelines recommend
an offender receive a prison sentence is determined by
scoring a range of offense and offender characteristics,
totaling the points, and comparing this total against

14

9

9

13

17
21
25
29
Worksheet A Point Total

33

37

41

an established threshold value. If the offender’s score
exceeds the threshold, the guidelines recommend a
prison sentence. The total score provides a judge with
an immediate summary assessment of each offender
that is directly comparable to the threshold value at the
bottom of the worksheet. Moreover, higher scores
indicate proportionally more serious offenders in the
context of the Virginia guidelines. The concept of
proportionality implies that as the total score increases,
there should also be an increase in the likelihood of prison.
The results show offenders in Virginia with lower total
worksheet scores are less likely to receive a prison
sentence than offenders with higher scores. Both the
Assault and Burglary figures provide strong evidence
of proportionality, however, there are differences
between the crime groups as shown in the adjacent
figures. The figures present both the actual percentage
as well as the estimated probability of prison for
offenders of varying seriousness, according to the
guidelines, for Assault and Burglary. For Assault,
the predicted probability of prison is only 30 percent
at the threshold value of 6 points and does not reach
50 percent until a total of 10 points is reached.
For the Assault crime group, the judges appear to
exercise discretion, as is their right under a voluntary
system, in determining whom to incarcerate.
In practice, the threshold acts more as a strong
signal than a strict legal standard.
For Burglary, the figure shows that below the threshold
of 14 points the probability of receiving a prison
sentence is stable at a very low rate. However, once
the point total exceeds 13, there is not only a dramatic
jump in the probability of prison but the probability
continues to rise as the worksheet total increases. In this
case, the threshold is operating as envisioned by the
guideline designers and creates a sharp discontinuity when
the total score exceeds the threshold value. The results
indicate judges are following the overall guideline
recommendation for the in/out decision.

Discrimination
A critical aspect of the NCSC research is to examine the
extent to which any observed inconsistency in sentencing
can also be called discriminatory. Discrimination is a
particularly troubling type of inconsistency as it implies
offenders are treated differently based largely on morally
and legally undesirable criteria. A potential confounding
factor is that sentencing outcomes may vary by region
around a state. One implication of the “similarly situated”
concept under statewide guidelines is that similarly
situated offenders are treated similarly in all parts
of the state. Therefore, geographic variation is also
examined as a source of unwarranted disparity.
The results reported here come from a battery of refined
statistical tests. In discussing and evaluating them, a
critical distinction between statistical versus substantive
significance should be underscored. Sensitivity to this
difference is warranted especially with controversial topics
like sentencing discrimination. Just because a factor is
found to be statistically significant does not mean the effect
is substantively significant; that is, that it has a large
effect on the outcome. A variable might be statistically
significant but have a very small impact that does not
reflect substantial differences in the real world.
The news from the current research is that while a small
number of statistically significant racial effects were
found across the three states, all were substantively small
with minimal impact on actual sentence decisions.
For example, while race alone is not significant in
Michigan and Minnesota, the subgroup of young black
males has a slightly greater chance of being sent to
prison of less than one percent. In Virginia, the guidelines
have eliminated almost all evidence of racial differences
in sentencing across the six crime groups examined with
one exception. Black males register a slight increase in
predicted sentence length for the Assault crime group.

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15

Assessing Consistency and Fairness in Sentencing:
A Comparative Study in Three States

With respect to males and females, there are statistically
significant findings across all three guideline systems
that female offenders are treated more leniently both with
respect to the in/out decision as well as the prison length
decision. However, the substantive impact of these
differences is typically small. For example, all other things
equal, women have less than a one percent lower
probability of being sentenced to prison in all three states.
Michigan is the only system where age was found to
have an impact. Older offenders are marginally more
likely to go to prison. However, even in this state, age
was not found to affect the length of sentence.
While there is little evidence of direct discrimination
due to race, age, or sex, the analysis suggests that there
is a less obvious source of discrimination brought on
by the differences in sentencing outcomes between the
large urban courts and the rest of the state — especially
in Michigan. To varying degrees, the operation of local
norms can sometimes circumvent the goal of statewide
uniformity in sentencing. And there is evidence that the
informal rules and norms in the large urban courts
shaping what sentences are deemed appropriate differ
from courts in the rest of the state. While the analysis
shows that the differences are statistically significant,
it is clear that, at least in Michigan, the differences are
substantively significant as well.
Offenders in metropolitan Southeast Michigan
(which include 60 percent of all black offenders)
receive sentences that are markedly more lenient than
their counterparts in the rest of the State (or out-state).
Results indicate the probability of going to prison is
10-15 percent higher in out-state Michigan and the
length of sentence is 25-30 percent greater. A single
set of guidelines is being applied in a very different
manner in different parts of the state.

16



The analysis suggests the primary reason for the presence of two statistically and substantively significant
sentencing regimes in Michigan can be traced to the
very large guideline sentencing ranges. The magnitude
of the ranges means that judges can sentence quite
differently without having to depart. If the norms of the
urban courts lead judges to look to the bottom of the
ranges, while out-state judges look toward the top, there
can be dramatic differences in sentencing outcomes.
While there is little evidence of discrimination as
usually conceived, geographical disparities undermine
the goal of statewide consistency.
In Minnesota the geographical differences are smaller
and different than in Michigan. Hennepin County, the
state’s most populous county, has a slightly higher rate
of imprisonment and slightly shorter sentences. In
order to mete out shorter sentences within the confines
of a guideline system with very narrow ranges, it is
not surprising that Hennepin judges depart below the
recommended guideline range twice as often as do
judges in the rest of the state.
One line of thought suggests that since the Virginia
sentencing guidelines are voluntary, there is more
room for judges across the Commonwealth to treat
convicted offenders differently. However there is
no evidence to suggest that there is systematic
discrimination — that rises to the level of statistical
significance — in Virginia. This is interesting given
that the explained variance in both Virginia crime
groups is less than that of the Michigan and Minnesota
counterparts. With more variation unexplained,
it seems likely to find some systematic discrimination,
however no supporting evidence for this was found
in the current research.

What conclusions can be drawn
from the study?
From the enquiry into the application of sentencing
guidelines in the three states of Michigan, Minnesota and
Virginia, there are five broad conclusions that increase
the understanding of how sentencing guidelines work
to shape and control the discretion of trial court judges.

The main conclusions are:
(1)	 Guideline systems produce predictable sentencing
decisions based upon their prescribed elements
and mechanics.
In addition, the guidelines result in differentiated
punishment. Like cases are treated alike while
unlike cases result in different degrees of punishment severity. Finally, the undesirable influence of
extra-legal factors is negligible in all three states.
(2)	 Predictability is somewhat higher in the context of
Minnesota’s more compact set of elements and use
of relatively narrow guideline ranges.
However, with the compactness comes a higher
propensity for departures. In contrast, Virginia’s
more detailed system allows for greater flexibility
in how the guidelines are to be applied (i.e., more
voluntary), thus building in more opportunities for
the exercise of appropriate discretion.

(4)	 All guideline systems benefit from periodic
assessment of current practice and the extent
to which the guideline systems are achieving
key goals of consistency and fairness.
Information on actual practices provides clear and
interpretable grounds for adjusting guideline
elements and mechanics. As a result, increased
accountability in future sentencing can be promoted on the basis of past performance and not
just on the basis of conjecture or supposition.
(5)	 Finally, policymakers, judges and all others concerned
about sentencing will benefit from working together
to ensure the establishment of sentencing commissions
to regularly monitor sentencing patterns to solidify
past and current gains as well as reorient future
resources in the most effective manner.
These conclusions underscore the value of comparative
research in criminal sentencing by clarifying the
similarities and differences in sentencing guideline
structures and their respective patterns of outcomes.
Only comparative enquiry provides an understanding
of where the differences lie and what their consequences
might be. Hence, it is hoped future researchers continue
to probe the conduct and outcomes of sentencing across
states and develop a broad base of data on which
conclusions are reached. More comparative enquiry
will help inform policymakers in their deliberations on
sentencing guidelines.

(3)	 There is no evidence of a direct trade-off between
predictability and proportionality on one hand and
undesirable racial, gender, or age disparities on the other.
In fact, a voluntary guideline system, such as the
one in Virginia, with substantial sentencing
ranges exhibits no measurable discrimination.



17

Assessing Consistency and Fairness in Sentencing:
A Comparative Study in Three States

The National Center
for State Courts is an
independent, nonprofit,
tax-exempt organization
in accordance with
Section 501 (c)(3) of
the Internal Revenue code.
The National Center
for State Courts is
headquartered in
Williamsburg, VA, with
offices in Denver, CO,
and Arlington, VA.

NCSC
300 Newport Ave.
Williamsburg, VA 23185-4147
www.ncsconline.org



© 2008 National Center for State Courts