Prevalence of Imprisonment in the U.S. Population, 1974-2001

Excerpt

Demographic techniques used to create prevalence estimates

Estimates of the prevalence of ever having gone to prison were derived from generation life table techniques. The prevalence of ever having gone to prison includes adults currently in prison and living former prisoners.

One-day counts of the number of adults in prison are available through the National Prisoner Statistics program (NPS). Collected annually since 1926, the NPS provides a count at yearend of persons held in Federal and State prisons.

To obtain the number of persons who had ever gone to prison, separate generation life tables were prepared for persons alive between 1974 and 2001. These tables model the first incarceration and mortality experience of each birth cohort as it proceeded through life. Estimates were made of the number of persons going to prison for the first time, by year of age, and the number who had been incarcerated and survived to each later age.

Rates of first incarceration during a 12-month period were developed from prison inmate surveys conducted in 1974, 1979, 1986, 1991, and 1997, a period during which admission rates increased after many years of relative stability.

Prevalence estimates for selected calendar years represent a sum of the contribution of each birth cohort to the total number of adults alive who had ever gone to prison. The number of former prisoners was obtained by subtracting the number of prisoners at yearend (NPS) from the total.

Estimates exclude admissions to local jails, due to the absence of data needed to calculate first admissions to jail. (See Methodology for estimation procedures and limitations.)

1 in 37 adult U.S. residents in 2001 had ever served time in prison

The 5.6 million adult U.S. residents who were current and former prisoners, represented an increase of 3.8 million since 1974. At yearend 2001, 2,673 persons per 100,000 adult U.S. residents had ever gone to prison, up from 1,251 per 100,000 adult residents in 1974. Overall, approximately 1 in 37 adult residents in 2001 had ever served time in a State or Federal prison.

As a percent of all adults who had ever gone to a State or Federal prison, the number of former prisoners has steadily declined (from 88% in 1974 to 77% in 2001). The decline occurred as the number of adults confined in prison at yearend grew by 1.1 million -- a 6-fold increase. Over the 27-year period the number of adult prison inmates rose from 216,000 to 1,319,000. By yearend 2001, there were 628 prison inmates per 100,000 adult residents, up from 149 in 1974.

Between 1974 and 2001 the number of former prisoners living in the United States more than doubled, from 1,603,000 to 4,299,000. Relative to the adult population, the number of former prisoners totaled 2,045 per 100,000 adult U.S. residents in 2001, up from 1,102 per 100,000 in 1974. At yearend 2001, 1 in every 49 adults in the United States was a former prisoner.

Two-thirds of the increase in number ever incarcerated due to rise in first incarceration rates

Nearly two-thirds of the 3.8 million increase in the number of adults ever incarcerated in prison between 1974 and 2001 occurred as a result of an increase in the rates of first incarceration....