Incarceration in the United States

It is now a commonly quoted statistic that the United States is home to five percent of the world’s population but houses twenty-five percent of its prisoners. A review of the most recent national statistics from 2013 shows that 6,899,000 Americans are under correctional supervision: 4,751,400 people were under the supervision of probation and parole, while 2,220,300 individuals were incarcerated in prisons and jails. The scope of this problem becomes more staggering in context: 1 in 9 American men and 1 in 56 American women is likely to spend time in prison in their lifetime. These numbers are more striking when you factor in racial disparities.

Understanding the crisis of mass incarceration (and mass probation) in the United States requires considering a complex array of issues from the history of incarceration and sentencing reform, to race relations and the social impacts of poverty, to the many efforts currently underway attempting to change the course of American criminal justice policy. Below are a number of valuable resources for providing important context and history. We will continue to update this list, and you can also find more information about the intersection of incarceration with health issues, race, age, and gender in our other backgrounders.

Conditions of Confinement



Statistics. (Updated monthly). Federal Bureau of Prisons.

National Prisoner Statistics Program. (Last Updated 2013). Department of Justice, Office of Justice Programs, Bureau of Justice Statistics.

Travis, J., Western, B., & Redburn, S. (Eds). (2014). The Growth of Incarceration in the United States: Exploring Causes and Consequences. National, Research Council. 202-232.

The Sentencing Project and Prison Policy Initiative are excellent resources for information about mass incarceration and current news/policy initiatives.

The Vera Institute of Justice has numerous projects on Sentencing and Corrections

Conditions of Confinement

Solitary Watch archives news and research about the use of solitary confinement in U.S. correctional facilities.

The Center for Constitutional Rights and the Prison Law Office pursue litigation on behalf of the rights of incarcerated individuals.

Just Detention works to end sexual abuse behind bars.


The United States Sentencing Commission

Families Against Mandatory Minimums


The ACLU’s Criminal Law Reform’s work covers sentencing, drug policing, and effective counsel. The ACLU Prison Project works to to ensure health, safety, and dignity for prisoners via litigation and advocacy.

The Pew Charitable Trusts’ Public Safety Initiative champions justice reform efforts.

Council of State Governments Justice Center, Corrections


The Urban Institute Justice Policy Center

The Center for Court Innovation initiates demonstration projects focused on alternatives to incarceration and evaluates those efforts.

Council of State Government Justice Center, Justice Reinvestment


The items below are list of recent, more in-depth research articles that take the reader deeper into the subject area. The list is neither comprehensive nor exhaustive. We will be updating articles on a monthly basis.

Violent Victimization in the Prison Context: An Examination of the Gendered Contexts of Prison
Teasdale B. Daigle LE, Hawk SR, Daquin JC. Int J Offender Ther Comp Criminol. 2015 Feb 24.
“Currently there are few published, multilevel studies of physical assault victimization of prisoners. This study builds on the extant research by utilizing a nationally representative sample of correctional facilities (n = 326) and inmates (n = 17,640) to examine the impacts of a large set of theoretically and empirically derived individual- and contextual-level variables on prison victimization, including how the gendered context of prison impacts victimization. Results support the lifestyles/routine activities approach. Inmates who were charged with a violent offense, were previously victimized, were smaller in size, were not married, were without a work assignment, misbehaved, did not participate in programs, used alcohol or drugs, and those who had a depression or personality disorder were more likely to be victimized. In addition, the data suggest that 8% of the variance in victimization is due to the prison context. Prisons with high proportions of violent offenders, males, inmates from multiracial backgrounds, and inmates with major infractions had increased odds of victimization. Moreover, the sex-composition of the prison has significant main and interactive effects predicting victimization. Specifically, we find that the effects of being convicted of a drug crime, drug use, military service, major infractions, and diagnosed personality disorders are all gendered in their impacts on victimization.”

Improving public health by respecting autonomy: Using social science research to enfranchise vulnerable prison populations
Shaw D. Elger B. Prev Med. 2015 Feb 21.
It is widely recognised that prisoners constitute a vulnerable population that is subject to numerous health inequalities and merits special protection. Improving prisoners’ access to healthcare by ensuring adherence to the principle of equivalence has been the main focus of efforts to ensure that their health is not jeopardised. However, another means of respecting prisoners’ autonomy and improving their health is to involve them (and prison staff) in social science research within prisons. Such research not only produces valuable data which can be used to assess whether the principle of equivalence is being respected; it also enfranchises prisoners by allowing them to air concerns about perceived ill-treatment and influence their environment. If prison authorities enable such research and adjust policy accordingly, both they and prisoners will benefit from the increased level of respect for prisoners’ autonomy, and the improvements in individual and public health that flow from this. Conducting social science research in prisons enables the creation of a virtuous cycle of respect that makes prisons safer and healthier places.

The Adam Walsh Act: An Examination of Sex Offender Risk Classification Systems
Zgoba KM, Milner M, Levenson J. Sex Abuse. 2015 Feb 5.
This study was designed to compare the Adam Walsh Act (AWA) classification tiers with actuarial risk assessment instruments and existing state classification schemes in their respective abilities to identify sex offenders at high risk to re-offend. Data from 1,789 adult sex offenders released from prison in four states were collected (Minnesota, New Jersey, Florida, and South Carolina). On average, the sexual recidivism rate was approximately 5% at 5 years and 10% at 10 years. AWA Tier 2 offenders had higher Static-99R scores and higher recidivism rates than Tier 3 offenders, and in Florida, these inverse correlations were statistically significant. Actuarial measures and existing state tier systems, in contrast, did a better job of identifying high-risk offenders and recidivists. As well, we examined the distribution of risk assessment scores within and across tier categories, finding that a majority of sex offenders fall into AWA Tier 3, but more than half score low or moderately low on the Static-99R. The results indicate that the AWA sex offender classification scheme is a poor indicator of relative risk and is likely to result in a system that is less effective in protecting the public than those currently implemented in the states studied.”

Protective strengths, risk, and recidivism in a sample of known sexual offenders
Miller HA. Sex Abuse. 2015 Feb.
“The relationship between protective strengths and risk, as assessed by the Inventory of Offender Risk, Needs, and Strengths, was examined with respect to the recidivism rate and type of reoffense in a sample of 110 adult males incarcerated for sexual offenses. The sample included offenders who were completing a prison-based sexual offense treatment program during the last 18 months of their incarceration. Approximately 40% of the sample recidivated in some way, including 6% sexually, within the 6-year follow-up time. Self-perceived protective strengths were significantly valid predictors for sexual, violent, and general recidivism. In regression analyses, protective strengths accounted for a unique portion of the variance in sexual recidivism while controlling for overall risk. Consistent with research on the importance of protective strengths with other offender types, the continued study and inclusion of protective strengths in the assessment and treatment of sexual offenders is warranted.”