Recidivism Among Federal Offenders 

Receiving Retroactive Sentence Reductions: 

The 2011 Fair Sentencing Act Guideline Amendment

UNITED STATES SENTENCING COMMISSION
William H. Pryor Jr. 

Acting Chair

Rachel E. Barkow

Commissioner

Charles R. Breyer

Commissioner

Danny C. Reeves

Commissioner

Zachary C. Bolitho

Ex Officio 

J. Patricia Wilson Smoot

Ex Officio

Kenneth P. Cohen 

Staff Director

Glenn R. Schmitt

Director

Office of Research and Data

March 2018

United States Sentencing Commission

One Columbus Circle, N.E.

Suite 2-500, South Lobby

Washington, DC 20002

www.ussc.gov
Kim Steven Hunt, Ph.D.

Senior Research Associate

Office of Research and Data

Kevin Maass, M.A.

Research Associate

Office of Research and Data 

Todd Kostyshak, J.D.

Assistant General Counsel

Office of General Counsel 

United States Sentencing Commission

Table of Contents

I. Introduction........................................................................................................................1

II. The Fair Sentencing Act Amendment to the Sentencing Guidelines...........................2

 Key Findings....................................................................................................................3

 

 Methodology.................................................................................................................4

 

 The Study Groups...........................................................................................................5

III. Detailed Recidivism Findings...........................................................................................7

 

 Overview of Recidivism Study Findings.......................................................................7

 

 Recidivism by Offender Characteristics.....................................................................8

 Recidivism by Other Characteristics...........................................................................11

IV. Conclusion.........................................................................................................................14

 

V. Appendix...........................................................................................................................16 

 

 A Natural Experiment...................................................................................................16

 Similarity of the Study Groups......................................................................................17

VI. Endnotes............................................................................................................................20

i
United States Sentencing Commission

ii
United States Sentencing Commission

1

Introduction

The Fair Sentencing Act of 20101 (“FSA”) reduced 

the statutory penalties for crack cocaine offenses in two 

ways. First, it increased the drug quantity thresholds 

required to trigger the statutory mandatory minimum 

terms of imprisonment for manufacturing or trafficking 

crack cocaine. Second, it eliminated the statutory 

mandatory minimum penalty for possession of crack 

cocaine. In the FSA, Congress directed the United States 

Sentencing Commission (the “Commission”) to amend the 

federal sentencing guidelines to incorporate the reduced 

statutory penalty structure for crack cocaine offenses 

effective November 1, 2010. Congress did not make the 

FSA statutory penalty reductions retroactive, but the 

Commission did give retroactive effect to the FSA guideline 

amendment (the “FSA Guideline Amendment”) as of 

November 1, 2011.2 Following that action, 7,748 crack 

cocaine offenders have received an estimated average sentence reduction 

of 30 months, lowering their sentence from an average of 153 months to 

123 months of imprisonment.3

In 2015, as required by the FSA, the Commission submitted a 

report to Congress assessing the impact of the FSA on the federal criminal 

justice system (the “2015 FSA Report”).4 The Commission noted in that 

report that its earlier research had found that a previous population of 

crack cocaine offenders released early as a result of retroactive application 

of a guideline amendment did not show a statistically significant increase 

in the likelihood of recidivating,5 but it was too soon to assess the 

recidivism of crack cocaine offenders released early through retroactive 

application of the FSA Guideline Amendment.6 In the 2015 FSA Report, 

the Commission further stated its intent to separately study the effect of 

retroactive application of the FSA Guideline Amendment on recidivism. 

This publication provides that analysis.

Kim Steven Hunt, Ph.D.

Senior Research Associate

Office of Research and Data

Kevin Maass, M.A.

Research Associate

Office of Research and Data 

Todd Kostyshak, J.D.

Assistant General Counsel

Office of General Counsel 

Finding: 

The Commission finds no difference between the recidivism rates 

for offenders who were released early due to retroactive application of 

the FSA Guideline Amendment and offenders who had served their full 

sentences before the FSA Guideline Amendment reduction retroactively 

took effect. 
United States Sentencing Commission

2

The Fair Sentencing Act Amendment to the 

Sentencing Guidelines

On August 3, 2010, Congress passed the FSA, which, among other 

things, reduced the disparity between the amount of crack cocaine and 

powder cocaine that triggered statutory mandatory minimum penalties 

from a 100-to-1 drug quantity ratio to an 18-to-1 drug quantity ratio. 

Specifically, the quantity threshold of crack cocaine required to trigger the 

5-year mandatory minimum term of imprisonment was increased from 5 

grams to 28 grams, and the quantity threshold required to trigger the 10-

year mandatory minimum term of imprisonment was increased from 50 

to 280 grams. The FSA also eliminated the 5-year mandatory minimum 

penalty for simple possession of crack cocaine. 

As directed by the 

FSA, the Commission 

conformed the drug 

guideline penalty 

structure for crack 

cocaine offenses to the 

amended statutory 

quantities. The Base 

Offense Levels for crack 

cocaine were set in the 

Drug Quantity Table 

so that the statutory 

minimum penalties 

corresponded to offense 

levels 26 and 32.7 Accordingly, using the new drug quantities established 

by the FSA, offenses involving 28 grams or more of crack cocaine were 

assigned a Base Offense Level of 26, offenses involving 280 grams or more 

of crack cocaine were assigned a Base Offense Level of 32. The offense 

levels for other quantities were established by extrapolating upward and 

downward as appropriate. The revised Drug Quantity Table was effective 

November 1, 2010.

Congress did not give retroactive effect to the statutory reductions 

made by the FSA, but the Commission did give retroactive effect to the 

FSA Guideline Amendment as of November 1, 2011.8 That action allowed 

incarcerated crack cocaine offenders whose guideline range would have 

been lower if the FSA Guideline Amendment had been in effect when they 

were originally sentenced to file a motion with the sentencing court for a 

reduced sentence pursuant to 18 U.S.C. § 3582(c)(2) and USSG §1B1.10 

(Reduction in Term of Imprisonment as a Result of Amended Guideline 

Range).9 Courts granted 7,748 (55.4%) of the 13,990 motions filed seeking 

Table 1. The Fair Sentencing Act (FSA) Amendment

Pre-FSA

Crack Quantity

Post-FSA

Crack Quantity

21 U.S.C. § 841

5-year minimum 5 g 28 g

10-year minimum 50 g 280 g

21 U.S.C. § 960

5-year minimum 5 g 28 g

10-year minimum 50 g 280 g
United States Sentencing Commission

3

retroactive application of the FSA Guideline Amendment. Offenders 

whose motions were granted received an estimated sentence reduction 

of 30 months (19.9%) from an average of 153 months to 123 months of 

imprisonment.

In order to determine whether this earlier release affected 

recidivism, the Commission studied two groups of offenders. The 

Commission studied a group of offenders who received a reduced sentence 

through retroactive application of the FSA Guideline Amendment (the 

“FSA Retroactivity Group”) and compared their recidivism rates with 

a group of similar crack cocaine offenders who had served their full 

sentences before the FSA guideline reduction retroactively took effect (the 

“Comparison Group”). The Commission followed each group for three 

years after release from incarceration to look for recidivism events.

Methodology and Study Groups Key Findings

The key findings of the Commission’s study are:

• The recidivism rates were virtually identical for offenders who were released early 

through retroactive application of the FSA Guideline Amendment and offenders who 

had served their full sentences before the FSA guideline reduction retroactively took 

effect. Over a three-year period following their release, the “FSA Retroactivity Group” 

and the “Comparison Group” each had a recidivism rate of 37.9 percent.

• Among offenders who did recidivate, for both groups a “court or supervision violation”10 

was most often the most serious recidivist event reported. Approximately one-third of 

the offenders who recidivated in both groups (32.9% for the FSA Retroactivity Group 

and 30.8% for the Comparison Group) had court or supervision violation as their most 

serious recidivist event.

• Among offenders who did recidivate, the times to recidivism for both groups were 

nearly identical. The median time to recidivism for offenders who recidivated in both 

groups was approximately 141⁄2 months.

Table 2. Recidivism Study Offenders

The offenders studied in this project are 7,823 offenders who:

• are citizens;

• re-entered the community after serving a sentence with or without the FSA Guideline

Amendment applying retroactively;

• were not reported dead, escaped, or detained; and

• have a pre-sentence investigation report that was submitted to the Commission with a

federal sentence that was not vacated.
United States Sentencing Commission

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Methodology

The Commission previously reduced the penalties for crack 

cocaine offenses in 2007, before the enactment of the FSA, and made 

those reductions retroactive (“2007 Crack Cocaine Amendment”).11 That 

amendment reduced by two levels the Base Offense Levels assigned by 

the Drug Quantity Table for each quantity of crack cocaine.12 In 2014 

the Commission reported on recidivism rates for offenders who received 

retroactive sentence reductions upon application of the 2007 Crack 

Cocaine Amendment and concluded that retroactive application of the 

2007 Crack Cocaine Amendment did not result in increased recidivism.13 

The research discussed in this publication addresses whether the 

retroactive application of the FSA Guideline Amendment resulted in 

increased recidivism and uses the same single measure of recidivism 

as was used in the 2014 Crack Cocaine Recidivism Report in order to 

facilitate comparisons.14 

For purposes of this study, recidivism is defined as any of the 

following criminal record events occurring within a three-year period 

following release from incarceration: 

• a re-conviction for a new offense;

• a re-arrest with no case disposition information available; or 

• a violation or revocation of an offender’s supervised release.

In other words, recidivism events include all reports of 1) arrests for new 

crimes that did not result in acquittal or dismissal of all charges, and 

2) court or supervision violations that resulted in court action reported 

on criminal history records.15 All recidivism events within a three-year 

period after release were counted, including felonies, misdemeanors, and 

court and supervision violations, but minor traffic offenses were excluded. 

The Commission used a follow-up period of three years for this 

study, a length of time sufficient to answer the question of whether 

retroactive application of the FSA Guideline Amendment increased the 

risk of recidivism.16 This report focuses on the time from release until the 

first recidivism event for offenders who did recidivate within three years. 

Studying the timing of recidivism can help in understanding the process 

of desistance, as some offenders may be able to remain in the community 

for a considerable time before recidivating, while others recidivate very 

quickly. 
United States Sentencing Commission

5

For offenders who did recidivate following their release, the 

Commission also examined the type of recidivism event and ranked those 

recidivism events in order from most to least serious.17 The ranking 

generally begins with the most serious violent crimes, proceeds to less 

serious violent crimes, and then ranks drug trafficking, property, nontrafficking drug offenses, and public order crimes. Next, the “most 

serious” recidivism events were compiled to indicate which events 

appeared most frequently as the “most serious” recidivism event 

committed during the three-year period after release. Reporting offense 

types in this manner is intended to allow the reader to assess the relative 

threat to public safety posed by offenders who did recidivate. 

Finally, the report discusses the association between recidivism 

and factors affecting sentence length, including both offender factors such 

as criminal history and other factors such as the use of a weapon, and 

notes how those factors relate to the FSA Retroactivity Group and the 

Comparison Group.

The Study Groups

The two groups of crack cocaine offenders studied for this report 

are described below in Table 3. 

FSA Retroactivity Group Comparison Group

Number of Offenders 5,525 offenders 2,298 offenders

Release Date Nov. 1, 2011 – Nov. 30, 2013 Nov. 1, 2010 – Oct. 31, 2011

Release Basis

Received retroactive sentence 

reduction through the FSA 

Guideline Amendment.

Served full sentence before

FSA Guideline Amendment;

Otherwise would have been 

eligible for sentence reduction 

motion.

Table 3. Study Groups
United States Sentencing Commission

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This report relies on a major advancement in technology since 

the Commission’s 2014 Crack Cocaine Recidivism Report. That report 

studied a random sample of 1,319 offenders who met that study’s criteria 

for one of its two groups. For this study, technological advances have 

allowed the Commission to study all federal offenders who were convicted 

of crack cocaine offenses and released during the study period and who 

met the study criteria, a total of 7,823 offenders. The technology involves 

a nationwide FBI network for criminal record retrieval. The Commission 

entered into a data sharing agreement with the FBI’s Criminal Justice 

Information Services Division (CJIS) and the Administrative Office of the 

United States Courts to provide the Commission with electronic access 

to criminal history records (“RAP sheets”) through the CJIS’s Interstate 

Identification Index (III). The system returns all known records of 

arrests, prosecutions, court actions, and supervision actions for which 

participating jurisdictions keep automated records. Using an automated 

software program that analyzed and classified offender criminal records, 

the Commission identified and processed the criminal records of these 

7,823 citizen offenders who had a valid FBI number in either Commission 

or Bureau of Prisons (BOP) records and who were released during the 

study period.

As discussed in greater detail in the Appendix, the FSA 

Retroactivity Group and the Comparison Group are closely 

matched with respect to offense, offender, and other 

characteristics. Both groups are similar in terms of personal 

characteristics such as age, gender, race, criminal history, 

and education. Some of these characteristics, such as age and 

criminal history, have been previously shown to be associated 

with recidivism rates.18 Because the two groups are generally 

well matched in terms of these and other characteristics, 

neither group should have been more prone to reoffend as a 

result of these underlying characteristics. Well-matched groups allow for 

a fair test of the proposed research question: Did the reduced sentences 

for the FSA Retroactivity Group result in increased recidivism?

Research Question:

Did the reduced 

sentences for the FSA 

Retroactivity Group 

result in increased 

recidivism?
United States Sentencing Commission

7

Detailed Recidivism Findings

Overview of Recidivism Study Findings

The recidivism rates of the FSA Retroactivity Group and the 

Comparison Group were virtually identical, even though the FSA 

Retroactivity Group was released early after serving an estimated 

average of 30 fewer months of imprisonment. The recidivism rate for both 

groups was 37.9 percent.19 

For both the FSA Retroactivity Group and the Comparison 

Group, the offenders who did recidivate most commonly had a “most 

serious” post-release recidivism event that was categorized as a court 

or supervision violation.20 Almost one-third of offenders in each group 

who recidivated—32.9 percent of the FSA Retroactivity Group and 30.8 

percent of the Comparison Group—had such a violation as their most 

serious post-release recidivism event during the three-year period. Both 

groups also had drug trafficking as the next most common most serious 

post-release recidivism event, followed by simple assault (typically 

classified as a misdemeanor).

FSA Retroactivity Group Comparison Group

Recidivism Rate 37.9% 37.9%

Median Time to Recidivism 14.4 Months 14.5 Months

Most Serious Post-Release Event 

(Percent)

Court or Supervision 

Violations

(32.9%)

Court or Supervision 

Violations

(30.8%)

Table 4. Overview of Recidivism Study Findings

SOURCE: U.S. Sentencing Commission’s 2010-13 FSA Retroactive Recidivism Release Cohort Datafile, FSARECID. The 

Commission excluded cases from this analysis that were missing information necessary to perform the analysis. 
United States Sentencing Commission

8

For the 37.9 percent of offenders in both groups who did recidivate, 

the median time from release to recidivism was nearly identical for 

both the FSA Retroactivity Group and the Comparison Group. Among 

offenders in the FSA Retroactivity Group who did recidivate, the median 

time to recidivism was 14.4 months, while the Comparison Group’s 

median time to recidivism was 14.5 months.

Recidivism by Offender Characteristics

The Commission also examined the recidivism rates for offenders 

in the two groups in light of several offender characteristics. For example, 

recidivism rates for the several demographic groups of offenders in this 

study were similar in both groups. Black offenders, who accounted for 

85.5 percent of offenders in the study, had recidivism rates of 38.7 percent 

in the FSA Retroactivity Group and 38.9 percent in the Comparison 

Group. White offenders, the next most numerous racial group at 7.1 

percent, had recidivism rates of 34.0 percent in the FSA Retroactivity 

Group and 33.5 percent in the Comparison Group.

Figure 1. Time to Recidivism by Group

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0 1 2 3

FSA Retroactivity Group Comparison Group

Median Time to Recidivism:

FSA Retroactivity Group:

14.4 Months

Comparison Group:

14.5 Months 37.9%

37.9%

SOURCE: U.S. Sentencing Commission’s 2010-13 FSA Retroactive Recidivism Release Cohort Release Date Datafile, FSARECID_EARLYOFF. The Commission 

excluded cases from this analysis that were missing information necessary to perform the analysis. 
United States Sentencing Commission

9

Male offenders, who comprised over 90 percent of each group, had 

recidivism rates of 38.6 percent in the FSA Retroactivity Group and 39.2 

percent in the Comparison Group. Female offenders had recidivism rates 

of 27.3 percent in the FSA Retroactivity Group and 23.7 percent in the 

Comparison Group.

Among offenders who had completed less than a high school 

education at the time they were sentenced, the recidivism rates were 

42.1 percent in the FSA Retroactivity Group and 43.7 percent in the 

34.0%

38.7%

29.5%

33.5%

38.9%

31.6%

0.0%

10.0%

20.0%

30.0%

40.0%

50.0%

60.0%

70.0%

80.0%

90.0%

100.0%

White Black Hispanic

FSA Retroactivity Group Comparison Group

n=356 n=197 n=4,768 n=1,913 n=353 n=155

Figure 2. Recidivism Rates by Race/Ethnicity

SOURCE: U.S. Sentencing Commission’s 2010-13 FSA Retroactive Recidivism Release Cohort Datafile, FSARECID. The Commission excluded cases from this 

analysis that were missing information necessary to perform the analysis. 

38.6%

27.3%

39.2%

23.7%

0.0%

10.0%

20.0%

30.0%

40.0%

50.0%

60.0%

70.0%

80.0%

90.0%

100.0%

Male Female

FSA Retroactivity Group Comparison Group

n= 5,180 n=2,095 n=345 n=203

Figure 3. Recidivism Rates by Gender

SOURCE: U.S. Sentencing Commission’s 2010-13 FSA Retroactive Recidivism Release Cohort Datafile, FSARECID. The Commission excluded cases from this analysis that 

were missing information necessary to perform the analysis. 
United States Sentencing Commission

10

Comparison Group. Among offenders who had completed high school 

but did not attend college, the recidivism rates were 35.3 percent in the 

FSA Retroactivity Group and 34.4 percent in the Comparison Group. For 

those offenders who had attended some college but had not graduated, 

the recidivism rates were 29.9 percent in the FSA Retroactivity Group 

and 25.9 percent in the Comparison Group. For those offenders who had 

graduated from college, the recidivism rates were 6.1 percent in the FSA 

Retroactivity Group and 13.3 percent in the Comparison Group.

The Commission has previously found offender age to be an 

important factor influencing recidivism.21 Among offenders released prior 

to age 30, the recidivism rates were 59.5 percent in the FSA Retroactivity 

Group and 55.6 percent in the Comparison Group. In contrast, among 

offenders released after reaching age 30, the recidivism rates were 33.1 

percent and 32.8 percent, respectively.

42.1%

35.3%

29.9%

6.1%

43.7%

34.4%

25.9%

13.3%

0.0%

10.0%

20.0%

30.0%

40.0%

50.0%

60.0%

70.0%

80.0%

90.0%

100.0%

Less than High School Graduate High School Graduate Some College College Graduate

FSA Retroactivity Group Comparison Group

n=2,712 n=1,148 n=2,094 n=821 n=652 n=305 n=33 n=15

Figure 4. Recidivism Rates by Educational Attainment

SOURCE: U.S. Sentencing Commission’s 2010-13 FSA Retroactive Recidivism Release Cohort Datafile FSARECID. The Commission excluded cases from this analysis that 

were missing information necessary to perform the analysis. 

59.5%

33.1%

55.6%

32.8%

0.0%

10.0%

20.0%

30.0%

40.0%

50.0%

60.0%

70.0%

80.0%

90.0%

100.0%

Younger than 30 30 or Older

FSA Retroactivity Group Comparison Group

n=1,000 n=513 n=4,520 n=1,785

Figure 5. Recidivism Rates by Age at Release

SOURCE: U.S. Sentencing Commission’s 2010-13 FSA Retroactive Recidivism Release Cohort Datafile, FSARECID. The Commission excluded cases from this analysis that 

were missing information necessary to perform the analysis. 
United States Sentencing Commission

11

The Commission has also previously found that the seriousness 

of an offender’s criminal record is an important factor influencing 

recidivism.22 The Commission assigns offenders to one of six Criminal 

History Categories (CHC), depending on the number and sentence length 

of their prior convictions. Among offenders in the lowest three categories, 

Criminal History Categories I, II, and III, the recidivism rates were 

30.4 percent for the FSA Retroactivity Group and 30.6 percent for the 

Comparison Group. In contrast, among offenders in Criminal History 

Categories IV, V, and VI, the recidivism rates were 46.3 percent for the 

FSA Retroactivity Group and 49.3 percent for the Comparison Group.

Recidivism by Other Characteristics

The recidivism rates for other factors were also generally similar 

in both groups. For example, whether the offense for which the offender 

was originally sentenced involved a weapon or not was not found to be 

a strong factor in either group. For offenders who committed an offense 

involving a weapon,23 the recidivism rates were 37.0 percent in the 

FSA Retroactivity Group and 36.6 percent in the Comparison Group. 

For offenders who did not commit an offense involving a weapon, the 

recidivism rates were 38.4 percent in the FSA Retroactivity Group and 

38.4 percent in the Comparison Group. 

30.4%

46.3%

30.6%

49.3%

0.0%

10.0%

20.0%

30.0%

40.0%

50.0%

60.0%

70.0%

80.0%

90.0%

100.0%

Criminal History Categories I-III Criminal History Categories IV-VI

FSA Retroactivity Group Comparison Group

n=2,894 n=1,389 n=2,611 n=903

Figure 6. Recidivism Rates by Criminal History Categories

SOURCE: U.S. Sentencing Commission’s 2010-13 FSA Retroactive Recidivism Release Cohort Datafile, FSARECID. The Commission excluded cases from this analysis that 

were missing information necessary to perform the analysis. 
United States Sentencing Commission

12

The length of the original sentence imposed relative to the 

guideline range that applied at the original sentencing was not found 

to be a strong factor influencing recidivism rates for either the FSA 

Retroactivity Group or the Comparison Group, and the recidivism rates 

were similar across the two groups. For offenders sentenced within 

the guideline range, the recidivism rates were 37.7 percent in the FSA 

Retroactivity Group and 38.1 percent in the Comparison Group. For 

offenders sentenced below the guideline range for providing substantial 

assistance to the government (under USSG §5K1.1), the recidivism rates 

were 38.6 percent in the FSA Retroactivity Group and 37.6 percent in 

the Comparison Group. The recidivism rates for offenders sentenced 

below the guideline range and not sponsored by the government were 

37.1 percent in the FSA Retroactivity Group and 36.9 percent in the 

Comparison Group. While the recidivism rate for offenders sentenced 

above the guideline range shows a large difference between the groups, 

the number of cases in this category is too low to allow conclusions to be 

drawn, with only 51 cases in the FSA Retroactivity Group and nine cases 

in the Comparison Group.

38.4% 38.4% 37.0% 36.6%

0.0%

10.0%

20.0%

30.0%

40.0%

50.0%

60.0%

70.0%

80.0%

90.0%

100.0%

No Weapon Weapon Specific Offense Characteristic

or Convicted Under 18 U.S.C. § 924(c)

FSA Retroactivity Group Comparison Group

n=3,562 n=1,636 n=1,963 n=662

Figure 7. Recidivism Rates by Weapon Involvement

SOURCE: U.S. Sentencing Commission’s 2010-13 FSA Retroactive Recidivism Release Cohort Datafile, FSARECID. The Commission excluded cases from this analysis that 

were missing information necessary to perform the analysis. 
United States Sentencing Commission

13

There was little difference between the rates of the two groups 

when considering recidivism in light of the length of the sentence 

imposed. For example, for offenders with original sentences of ten years 

or more, the recidivism rates were 32.2 percent in the FSA Retroactivity 

Group and 33.8 percent in the Comparison Group. For offenders with 

original sentences of less than ten years, the recidivism rates were 

43.8 percent in the FSA Retroactivity Group and 40.8 percent in the 

Comparison Group. 

37.7%

41.2% 38.6%

44.8%

38.1% 37.1%

55.6%

37.6%

41.7%

36.9%

0.0%

10.0%

20.0%

30.0%

40.0%

50.0%

60.0%

70.0%

80.0%

90.0%

100.0%

Within Above §5K1.1 Other Gov't Sponsored Other Below

FSA Retroactivity Group Comparison Group

n=3,588 n=1,451 n=51 n=9 n=1,116 n=466 n=116 n=36 n=617 n=314

Figure 8. Recidivism Rates by Sentence Relative to the Guideline Range

SOURCE: U.S. Sentencing Commission’s 2010-13 FSA Retroactive Recidivism Release Cohort Datafile, FSARECID. The Commission excluded cases from this analysis that 

were missing information necessary to perform the analysis. 

43.8%

32.2%

40.8%

33.8%

0.0%

10.0%

20.0%

30.0%

40.0%

50.0%

60.0%

70.0%

80.0%

90.0%

100.0%

Less than 10 Years 10 Years or More

FSA Retroactivity Group Comparison Group

n=2,729 n=1,321 n=2,781 n= 976

Figure 9. Recidivism Rates by Sentence Length

SOURCE: U.S. Sentencing Commission’s 2010-13 FSA Retroactive Recidivism Release Cohort Datafile, FSARECID. The Commission excluded cases from this analysis that were 

missing information necessary to perform the analysis. 
United States Sentencing Commission

14

Conclusion

The Commission found no difference in the recidivism rates of 

offenders who were released an estimated average of 30 months early 

through retroactive application of the FSA Guideline Amendment and 

similar offenders who served their full sentences and were released before 

the FSA guideline reductions took effect. The recidivism rate for both 

groups was 37.9 percent within three years of release from incarceration.

The Commission’s findings in this study are consistent with the 

Commission’s other recent studies of federal crack cocaine offenders.24 

In 2014, the Commission conducted a recidivism study of offenders who 

received sentence reductions and were released early through retroactive 

application of the 2007 Crack Cocaine Amendment.25 In that study, the 

Commission examined federal crack cocaine offenders released between 

2007 and 2008 and found similar recidivism rates three years after 

release for both the retroactivity and comparison groups, 36.7 percent 

and 39.8 percent, respectively. The difference in the rates of recidivism, 

derived from a sample of offenders, was not found to be statistically 

significant. Both rates closely compare to the results of this study (37.9%) 

and the same measure of recidivism was used in both studies.

In 2017, the Commission released a publication that studied 

federal crack cocaine offenders released during 2005 and reported 

the rates of three measures of recidivism—rearrest, reconviction, and 

reincarceration—three years after release.26 That study found that the 

rearrest rate (the measure of recidivism most analogous to the measure 

of recidivism in this study) for federal crack cocaine offenders released in 

2005 was found to be 40.0 percent, similar to both the current study and 

the 2014 study.
United States Sentencing Commission

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United States Sentencing Commission

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Appendix

A Natural Experiment

This FSA retroactivity recidivism study, as with the previous 2014 

Crack Cocaine Recidivism study, takes the form of a natural experiment. 

In a standard experiment such as a randomized clinical trial, subjects are 

allocated at random (by chance alone) to receive a clinical intervention 

while others are assigned to the standard protocol and act as a 

comparison group. In a natural experiment, by contrast, the assignment 

to the treatment and comparison groups occurs “as if” at random27 but 

is not controlled directly. Natural experiments rely on a credible claim 

that the assignment of the nonexperimental subjects to treatment and 

comparison conditions is “as if” the assignment was random.28 Outcomes 

are compared across treatment and comparison groups, and the 

comparison is judged to be a fair one if the assignment to treatment and 

comparison groups does appear to be “as if” at random. 

In the FSA retroactivity policy change, the two groups (the FSA 

Retroactivity Group who received FSA sentence reduction retroactively 

and the Comparison Group who were released from prison prior to the 

eligibility period, but otherwise met the eligibility requirements for 

sentence reduction) are primarily separated by the start time of the policy 

change, November 1, 2011. Most qualified inmates who sought sentence 

reductions under the FSA Retroactivity Amendment received it, and most 

who were refused were not eligible. Given the close equivalence between 

eligibility and subsequent sentence reduction, it is credible to assume 

that, similarly, if the same reductions had been available one year earlier, 

most of the Comparison Group would have also received it.29

The foundation of the close equivalence between the FSA 

Retroactivity and Comparison Groups lies with the eligibility criteria 

for the Comparison Group. Eligibility criteria required that: the drug 

involved was crack cocaine; the Base Offense Level was between 12 

and 38; the offender was not convicted under the Career Offender 

(USSG §4B1.1) or Armed Career Criminal (USSG §4B1.4) guidelines; 

the original guideline range could change under the FSA;30 and the 

offender’s applicable Base Offense Level could change under the FSA.31 

These eligibility criteria identified the 2,298 offenders included in the 

Comparison Group. To receive a reduced sentence under the retroactive 

provisions of the FSA Guideline Amendment, offenders within the 
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eligibility period also had to file a motion for a reduced sentence. Of the 

13,990 such motions decided through October 31, 2014 (the last date for 

which such information was compiled), only 7,748 (55.4%) of the 13,990 

motions received were granted. However, of the 6,242 (44.6%) motions 

denied, most (4,635) were denied due to ineligibility under §1B1.10. No 

more than 367 (5.9%) of the 6,242 reasons for denial were due to concerns 

for public safety.32 Thus, applying this denial percentage of 5.9 percent 

to our Comparison Group, no more than approximately 136 of the 2,298 

offenders in the Comparison Group would likely have been denied a 

sentence reduction due to concerns for public safety.

Similarity of the Study Groups

As described above, the Comparison Group was selected to match 

the FSA Retroactivity Group as closely as possible in important ways. 

Both offender characteristics (especially those that have previously been 

found to be correlated with recidivism) and other characteristics should 

be as similar as possible to result in a fair comparison of recidivism rates 

between the groups.

Offender characteristics of particular interest include 

race/ethnicity, gender, education, age, and Criminal History Category. 

The groups were demographically similar, including race/ethnicity and 

gender, and were well-matched across offender characteristics that have 

previously been shown to be associated with recidivism such as education 

level, age, and criminal history.33

Both groups are predominantly Black and male. The FSA 

Retroactivity Group has only a slightly higher proportion of Black 

offenders (86.4%) than the Comparison Group (83.5%). The FSA 

Retroactivity Group has only a slightly higher proportion of males 

(93.8%) than the Comparison Group (91.2%). The FSA Retroactivity 

Group has only a slightly lower proportion of offenders who did not 

complete high school (49.4%) than the Comparison Group (50.2%). The 

FSA Retroactivity Group has a slightly lower proportion of offenders 

released before age 30 (18.1%) than the Comparison Group (22.3%). The 

FSA Retroactivity Group has a higher proportion of offenders in CHC IV 

through VI (47.4%) than the Comparison Group (39.4%).

The likely reason that the FSA Retroactivity Group has a higher 

proportion of more serious criminal histories is related to the flow of 

offenders through the prison population. Daily counts of current prison 
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population show a larger percentage of offenders with longer sentences 

than those entering prison on that day (the admission count). The current 

prison population at any given time tends to overrepresent more serious 

offenders with longer sentences because these offenders accumulate 

in prison over time while those with shorter sentences are released 

relatively quickly.34 Retroactive releases of the FSA Retroactivity Group 

show many offenders being released quickly within the initial weeks of 

the effective date of the Amendment. Retroactive releases of the FSA 

Retroactivity Group resulted in 451 offenders released on November 1, 

2011 as the backlog of more offenders with longer sentences was released 

in large numbers, compared to the Comparison Group release of ten 

offenders one year earlier on November 1, 2010.35 Therefore, it is likely 

that the higher criminal history of the FSA Retroactivity Group is due 

to the large numbers of serious offenders with longer sentences being 

released in unusually high numbers.

Other characteristics are also important in judging the 

comparability of the FSA Retroactivity Group to the Comparison Group. 

The position of the original sentence relative to the guideline range 

was similar between the two groups. Most offenders in both groups 

were originally sentenced within the guideline rage (65.4% in the FSA 

Retroactivity Group and 63.8% in the Comparison Group). However, 

with respect to both weapon involvement as part of the instant offense 

and the original sentence length, the two groups are somewhat different. 

The FSA Retroactivity Group is more likely to have received a sentence 

increase for weapon involvement (35.5%) as part of the instant offense 

than the Comparison Group (28.8%). More offenders in the FSA 

Retroactivity Group received original sentences of ten years or more 

(50.3%), than did those offenders in the Comparison Group (42.5%). As 

previously discussed, the higher totals for both weapon involvement and 

sentences of ten years or more are probably due to the large numbers 

of serious offenders released in unusually high numbers in the period 

following the effective date of retroactive releases on November 1, 2011.

In summary, with respect to the offender and other characteristics 

measured, these two groups are well-matched. However, the FSA 

Retroactivity Group is more likely to have a serious criminal history, 

weapon involvement in the instant offense, and longer sentences than 

the Comparison Group. At least in the case of more serious criminal 

history, which has been shown in the Commission’s recent publications 

to be strongly associated with higher rates of recidivism,36 this difference 

should disadvantage the FSA Retroactivity Group. Therefore, it seems 
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reasonable to conclude that the two groups are generally well matched 

for purposes of comparing recidivism rates, and when offender and other 

characteristics between the two groups diverge somewhat, it is unlikely to 

redound to the benefit of the FSA Retroactivity Group and the criteria for 

a natural experiment are satisfied.

 
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Endnotes

1 Fair Sentencing Act of 2010, Pub. L. No. 111–220.

2 U.S. Sentencing Comm’n, Guidelines Manual, App. C, amend. 759 

(effective Nov. 1, 2011) [hereinafter USSG] (making retroactive USSG, App. C, 

amend. 750 (effective Nov. 1, 2011) (implementing as permanent the temporary, 

emergency amendment (USSG, App. C, amend. 748 (effective Nov. 1, 2010)) that 

implemented the FSA)).

3 See U.S. Sentencing Comm’n, Final Crack Retroactivity Data Report

Fair Sentencing Act (2014), https://www.ussc.gov/sites/default/files/pdf/researchand-publications/retroactivity-analyses/fair-sentencing-act/Final_USSC_Crack_

Retro_Data_Report_FSA.pdf. [hereinafter Final Crack Retroactivity Report].

4 U.S. Sentencing Comm’n, Report to the Congress: Impact of the Fair

Sentencing Act of 2010 (2015), https://www.ussc.gov/research/congressionalreports/2015-report-congress-impact-fair-sentencing-act-2010 [hereinafter 2015 

FSA Report].

5 See U.S. Sentencing Comm’n, Recidivism Among Offenders Receiving

Retroactive Sentence Reductions: The 2007 Crack Cocaine Amendment (2014), 

https://www.ussc.gov/sites/default/files/pdf/research-and-publications/researchprojects-and-surveys/miscellaneous/20140527_Recidivism_2007_Crack_Cocaine_

Amendment.pdf [hereinafter 2014 Crack Cocaine Recidivism Report].

6 2015 FSA Report, supra note 4, at 8.

7 On April 30, 2014 the Commission promulgated an amendment to 

further reduce by two the offense levels assigned in the Drug Quantity Table and 

voted to give retroactive effect to the reductions as of November 1, 2014. USSG, 

App. C, amend. 782 (effective Nov. 1, 2014) (“Drugs Minus Two” or “2014 Drug 

Guideline Amendment”). The further retroactive reduction of the Drugs Minus 

Two amendment is beyond the scope of this study.

8 USSG, App. C, amend. 759 (effective Nov. 1, 2011).

9 18 U.S.C. § 3582(c)(2) provides that, when the Commission lowers a 

sentencing guideline range, a court may reduce the term of imprisonment of a 

defendant sentenced to a term of imprisonment based on that range upon motion 

of the defendant, or the Director of the Bureau of Prisons, or on its own motion, 

provided that the reduction is consistent with any applicable policy statement 

issued by the Commission.

10 This category includes supervision violations, contempt of court, 

failure to appear, violation of a restraining order, and sex offender registration 

violations. 
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11 USSG, App C. amend. 706 (effective Nov. 1, 2007), as amended by 

amend. 711 (effective Nov. 1, 2007). 

12 See 18 U.S.C. § 3582(c)(2) (authorizing courts to modify the sentence of 

offenders which were based on a sentencing range that has been subsequently 

lowered by the Sentencing Commission).

13 See 2014 Crack Cocaine Recidivism Report, https://www.ussc.gov/

sites/default/files/pdf/research-and-publications/research-projects-and-surveys/

miscellaneous/20140527_Recidivism_2007_Crack_Cocaine_Amendment.pdf 

[hereinafter 2014 Crack Cocaine Recidivism Report].

14 Id. at 3.

15 Typically, the violations appeared as an arrest (e.g., the court ordered 

a law enforcement agency such as the United States Marshals Service to 

apprehend the offender).

16 The National Advisory Commission on Criminal Justice Standards 

and Goals recommends a follow-up time of three years. See Michael D. Maltz, 

Recidivism 22 (2001). The eight-year follow-up period used in recent publications 

such as U.S. Sentencing Comm’n, Recidivism Among Federal Offenders: A

Comprehensive Overview (2016), https://www.ussc.gov/sites/default/files/pdf/

research-and-publications/research-publications/2016/recidivism_overview.

pdf [hereinafter 2016 Recidivism Overview], while providing a more complete 

analysis, would delay the reporting of recidivism rates for the two groups of an 

additional five years.

17 In general, the Commission followed a widely accepted ranking scheme 

used in the Commission’s recent recidivism reports. See 2016 Recidivism

Overview, supra note 16; U.S. Sentencing Comm’n, Recidivism Among Federal

Drug Trafficking Offenders (2017), https://www.ussc.gov/sites/default/files/pdf/

research-and-publications/research-publications/2017/20170221_RecidivismDrugs.pdf; [hereinafter 2017 Drug Trafficking Recidivism Report]; U.S. 

Sentencing Comm’n, The Past Predicts the Future: Criminal History and

Recidivism of Federal Offenders (2017) [hereinafter 2017 Criminal History and

Recidivism of Federal Offenders], https://www.ussc.gov/sites/default/files/pdf/

research-and-publications/research-publications/2017/20170309_Recidivism-CH.

pdf; and U.S. Sentencing Comm’n, The Effects of Aging on Recidivism Among

Federal Offenders (2017), https://www.ussc.gov/sites/default/files/pdf/researchand-publications/research-publications/2017/20171207_Recidivism-Age.pdf. 

[hereinafter 2017 Effects of Aging on Recidivism Among Federal Offenders].

18 See 2016 Recidivism Overview, supra note 16, at 18 to 19 and 23.

19 Offenders served their full sentences, less reductions for earned credit.

20 Court or supervision violations include revocations of supervised release 

for technical violations, failure to appear, contempt of court, etc.
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21 See 2017 Effects of Aging on Recidivism Among Federal Offenders, supra

note 17.

22 See 2017 Criminal History and Recidivism of Federal Offenders, supra

note 17.

23 “Offense involving a weapon” is defined here as a conviction under 

18 U.S.C. § 924(c) or the application by the sentencing court of a Specific Offense 

Characteristic (SOC) in the sentencing guidelines indicating the involvement of a 

weapon in the offense.

24 Previous recidivism studies conducted by the Commission have studied 

similar three-year recidivism rates for federal crack cocaine offenders using 

different study cohorts, that is federal crack cocaine offenders released during 

different time periods.

25 See 2014 Crack Cocaine Recidivism Report, supra note 13. 

26 See 2017 Drug Trafficking Recidivism Report, supra note 17.

27 Thad Dunning, Improving Causal Inference: Strengths and Limitations of 

Natural Experiments, 61 Pol. Res. Q. 282-93 (2008). 

28 Id. at 283.

29 See Final Crack Retroactivity Report, supra note 2.

30 Situations in which the guideline range could not change include when 

the offender had a guideline range less than or equal to the statutory mandatory 

minimum penalty and received a sentence below the minimum pursuant to 

18 U.S.C. § 3553(e) in conjunction with a departure for substantial assistance 

pursuant to USSG §5K1.1 (Substantial Assistance to Authorities).

31 The Base Offense Level could not change for (1) cases in which more than 

one drug was involved and the combined weights of these drugs was such that 

the Base Offense Level did not change; or (2) cases in which the drug quantity of 

the single drug involved in the offense was sufficient that the offender remained 

at Base Offense Level 38.

32 The reasons given by courts for denials due to public safety concerns 

were: 18 U.S.C. § 3553(a) factors (170), protection of the public (114), and postsentencing or post-conviction conduct (83). See Final Crack Retroactivity

Report, supra note 2. Some offenders may have been denied under more than 

one of these reasons related to public safety.

33 See 2016 Recidivism Overview, supra note 16; see also 2017 Effects of

Aging on Recidivism Report, supra note 17.

34 See James P. Lynch, A Comparison of Prison Use in England, Canada, 

West Germany, and the United States: A Limited Test of the Punitive Hypothesis, 

79 J. Crim. Law & Criminology 180-217 (1988) (“Static or stock studies of 
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incarceration measure the use of imprisonment by the number of prisoners in 

custody on a given day. Flow designs use the number of admissions to prison 

over a particular unit of time.... However, because the probability of an offender 

being in prison on a given day is a function of the length of his sentence, stock 

statistics tend to overrepresent more serious offenders with longer sentences.”).

35 Similarly, retroactive releases returned to normal on November 1, 2012, 

with nine offenders from the FSA Retroactivity Group released on that day.

36 See 2017 Criminal History and Recidivism of Federal Offenders, supra

note 17.
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