2001-1988 0-13 56,557,383 0.000 0
1987 14 4,063,179 0.000 0
1986 15 4,071,585 0.000 0
1985 16 4,083,677 0.036 1,000
1984 17 4,117,221 0.174 7,000
1983 18 4,022,021 0.453 18,000
1982 19 4,327,407 0.794 34,000
1981 20 4,264,552 1.146 49,000
1980 21 4,140,721 1.510 63,000
1979 22 3,935,452 1.845 73,000
1978 23 3,756,052 2.155 81,000
1977 24 3,766,377 2.428 91,000
1976 25 3,643,765 2.676 97,000
1975 26 3,572,926 2.911 104,000
1974 27 3,579,019 3.082 110,000
1973 28 3,386,129 3.252 110,000
1972 29 3,876,011 3.360 130,000
1971 30 3,989,205 3.506 140,000
1970 31 4,032,301 3.584 145,000
1969 32 3,993,019 3.689 147,000
1968 33 3,899,282 3.764 147,000
1967 34 4,057,246 3.824 155,000
1966 35 4,110,892 3.857 159,000
1965 36 4,182,093 3.895 163,000
1964 37 4,416,302 3.887 172,000
1963 38 4,265,440 3.840 164,000
1962 39 4,826,377 3.778 182,000
1961 40 4,725,422 3.692 174,000
1960 41 4,634,371 3.641 169,000
1959 42 4,597,285 3.563 164,000
1958 43 4,518,648 3.507 158,000
1957 44 4,668,310 3.439 161,000
1956 45 4,464,137 3.356 150,000
1955 46 4,227,667 3.267 138,000
1954 47 4,192,570 3.180 133,000
1953 48 3,863,432 3.068 119,000
1952 49 4,131,847 2.953 122,000
1951 50 3,838,209 2.819 108,000
1950 51 3,595,173 2.688 97,000
1949 52 3,516,992 2.584 91,000
1948 53 3,497,820 2.475 87,000
1947 54 3,668,994 2.397 88,000
1946 55 3,180,818 2.341 74,000
1945 56 2,746,790 2.280 63,000
1944 57 2,788,492 2.220 62,000
1943 58 2,665,273 2.173 58,000
1942 59 2,710,967 2.131 58,000
1941 60 2,398,614 2.086 50,000
1940-1931 61-70 19,778,402 ... 377,000
1930-1901 71 or older 23,755,091 ... 384,000
[a] The number of U.S. residents on December 31, 2001, by age, were
based on projections for July 1, 2000, and July 1, 2001.
(See Projections of the Resident Population by Age, Sex,, Race and
Hispanic Origin: 1999 to 2100, U.S. Census Bureau, NP-D1-A, middle
series.) The data were adjusted for the undercount in the 1990
decennial census.
[b] Based on separate generation life tables starting in the year of
birth of the persons at each year of age. (See Appendix tables 2
and 3 for calculations for selected years of birth.)
[c] Estimates were calculated by multiplying column (1) by column (2)
and rounded to the nearest 1,000.
... Not shown, because all calculations were based on rates for single
years of age.
----------------------------------------------------------------------
To model the incarceration experience of the adult resident population
in 2001, a separate generation life table was needed for each birth
cohort born from 1901 to 1983. For example, of those born in 1980 and
alive in 2001, an estimated 1.510% had ever gone to prison (Appendix
table 1, column 2). Multiplying by 4,140,721 U.S. residents age 21 in
2001 (column 1), produced an estimate of 63,000 persons, age 21 in
2001, who had ever been incarcerated (column 3).
Similarly, the generation life table for the 1970 birth cohort produced
an estimated prevalence of 3.584% among those age 31 in 2001.
Multiplying by 4,032,301 U.S. residents age 31 in 2001 resulted in an
estimated 145,000 persons age 31 in 2001 who had ever been
incarcerated. The estimated 5,618,000 adults ever incarcerated in 2001
was obtained by summing the number of persons ever incarcerated, age 18
or older. Dividing by the adult resident population of 210,207,901
yielded an estimated prevalence of ever having gone to prison of 2.673%
in 2001.
----------------------------------------------------------------------
+Estimating prevalence of imprisonment in the United States+
To illustrate the application of generation life table techniques
resulting in the 1.510% rate of ever having gone to prison among
persons born in 1980, consider the following calculations:
1. Estimates of the number of persons in a population of 100,000 born
in 1980 who died during each age interval were obtained by multiplying
the age-specific mortality rate (Appendix table 2, column 2) by the
number of persons alive and not previously incarcerated at each age
(column 1).
* For example, among persons who reached age 21 without having been
previously incarcerated, a total of 92 were estimated to have died
(column 3) before reaching age 22 (that is, 96,607 times the mortality
rate of 0.000955).
2. The number of persons in the 1980 cohort who were at risk to
incarceration during an age interval was then calculated by subtracting
the number dying from the number of persons who were alive and not
previously incarcerated at the beginning of the age interval (column 1
minus column 3).
* An estimated 96,515 of the persons who survived to age 21 without
being incarcerated were at risk to first incarceration at age 21.
3. The number of persons in the original 100,000 population estimated
to have been admitted to prison at each age (column 5) was then
obtained by multiplying the age-specific first admission rates (column
4)by the number of persons alive and not previously incarcerated.
* Among persons born in 1980 who had not been previously incarcerated
by age 21, 343 were estimated to have been incarcerated before they
reached age 22 (that is, 96,515 times the first incarceration rate of
.003557).
4. The number of living persons at each age who had ever gone to
prison was then calculated by summing the number going to prison for
the first time during that year of age (column 5) plus the number of
members of the 1980 birth cohort who previously went to prison and
survived until the next year of age (column 6 times the survival rate,
not shown).
* Of the 1,132 persons who had gone to prison and reached age 20,
1,131 survived to reach age 21. An additional 343 persons were expected
to be incarcerated for the first time before reaching age 22 (for a
cumulative total of 1,474).
5. The percent of persons at each specific age who had ever gone to
prison (column 7) was then calculated by dividing the number of persons
who had ever gone to prison and were still alive (column 6) by all
persons who were still alive (including persons never incarcerated plus
ever incarcerated).
* Among persons age 21, the prevalence rate was 1.510%, obtained by
dividing 1,474 (column 6) by 97,646 (column 1 minus columns 3 and 5,
plus 1,474), times 100%.
Prevalence rates for other birth cohorts were calculated using similar
procedures. For example, to estimate the percent of persons age 31 in
2001 who had ever gone to prison, the calculations were applied to the
1970 birth cohort. However, the rates of first incarceration (column
4) and mortality (column 2) used in the calculations were unique to the
birth cohort. (Note the differences between Appendix tables 2 and 3.)
----------------------------------------------------------------------
<B>Appendix table 2. Estimating the prevalence of imprisonment in the
U.S. population for persons born in 1980</B>
Population of 100,000 births, 1980, reduced by mortality and
incarceration in each successive year of age
Number alive
and not Rate of first Surviving
incarcerated admission to Expected cumulative
at beginning Number Expected State or number of number of
Age at of age dying per number of Federal prison first first Prevalence
first interval 100,000 deaths[a] per 100,000 admissions[b] admissions[c] percent[d]
admission Year (1) (2) (3) (4) (5) (6) (7)
0-13 1980-93 100,000 ... 1,732 0 0 0 0.000%
14 1994 98,268 44 43 1 1 1 0.001
15 1995 98,224 57 56 5 5 6 0.006
16 1996 98,163 73 72 39 38 44 0.045
17 1997 98,053 84 83 135 132 176 0.180
18 1998 97,838 93 91 283 277 453 0.462
19 1999 97,470 93 91 346 337 789 0.806
20 2000 97,043 94 91 355 344 1132 1.158
21 2001 96,607 96 92 356 343 1474 1.510
Note: Calculations for ages 0 to 13 were based on data for each
single year of age and then grouped for presentation.
... Not shown, because calculations were based on rates for single
years of age.
[a] To estimate the number expected to die at each year of age,
age-specific mortality rates(column 2) were multiplied by the number
of persons alive and not previously incarcerated (column 1).
[b] To estimate the number expected to go to prison at each year of
age, age-specific first admission rates (column 4) were multiplied
by the number of persons surviving (column 1 minus column 3).
[c] To estimate the surviving number of first admissions, the number
of first admissions from the x-th year of age (column 5) were added
to the number of surviving first admissions from the x-1 year of age.
Mortality rates for ex-prisoners by age were based on mortality rates
in the general population and adjusted to reflect higher ex-prisoner
mortality.
[d]To estimate the prevalence percent, this procedure was followed.
The surviving number of persons ever incarcerated (column 6) was
divided by the total number of surviving persons never incarcerated
(column 1 minus both columns 3 and 5) and persons ever incarcerated
(column 6), times 100%.
----------------------------------------------------------------------
----------------------------------------------------------------------
<B>Appendix table 3. Estimating the prevalence of imprisonment in the
U.S. population for persons born in 1970</B>
Population of 100,000 births, 1970, reduced by mortality and
incarceration in each successive year of age
Number alive Rate of first
and not admission Surviving
incarcerated to State Expected cumulative
at beginning Number Expected or Federal number of number of
of age dying per number of prison per first first Prevalence
Age at first interval 100,000 deaths[a] 100,000 admissions[b] admissions[c] percent[d]
admission Year (1) (2) (3) (4) (5) (6) (7)
0-13 1970-83 100,000 ... 2,099 0 0 0 0.000%
14 1984 97,901 49 48 1 1 1 0.001
15 1985 97,852 62 61 0 0 1 0.001
16 1986 97,791 73 71 24 23 24 0.025
17 1987 97,697 86 84 74 73 97 0.099
18 1988 97,539 96 94 186 181 278 0.285
19 1989 97,265 102 99 265 258 535 0.549
20 1990 96,907 107 103 331 320 855 0.878
21 1991 96,484 110 107 266 257 1,110 1.142
22 1992 96,121 113 109 305 293 1,402 1.444
23 1993 95,719 111 106 272 260 1,660 1.711
24 1994 95,353 108 103 279 266 1,924 1.985
25 1995 94,984 104 99 230 218 2,139 2.210
26 1996 94,668 100 94 232 219 2,356 2.436
27 1997 94,354 100 94 217 205 2,558 2.648
28 1998 94,055 97 92 257 241 2,796 2.897
29 1999 93,722 102 95 218 204 2,997 3.108
30 2000 93,422 104 97 275 257 3,250 3.374
31 2001 93,068 110 102 218 203 3,448 3.584
Note: Calculations for ages 0 to 13 were based on data for each
single year of age and then grouped for presentation.
... Not shown, because calculations were based on rates for
single years of age.
[a] To estimate the number expected to die at each year of age,
age-specific mortality rates(column 2) were multiplied by the number
of persons alive and not previously incarcerated (column 1).
[b] To estimate the number expected to go to prison at each year of
age, age-specific first admission rates (column 4) were multiplied
by the number of persons surviving (column 1 minus column 3).
[c] To estimate the surviving number of first admissions, the number
of first admissions from the x-th year of age (column 5) were added
to the number of surviving first admissions from the x-1 year of age.
Mortality rates for ex-prisoners by age were based on mortality rates
in the general population and adjusted to reflect higher ex-prisoner
mortality.
[d] To estimate the prevalence percent, this procedure was followed.
The surviving number of persons ever incarcerated (column 6) was
divided by the total number of surviving persons never incarcerated
(column 1 minus both columns 3 and 5) and persons ever incarcerated
(column 6), times 100%.
----------------------------------------------------------------------
_Limitations_
1. The data in this report are restricted to incarcerations in State or
Federal prison. Excluded are prior incarcerations in local jails and
juvenile facilities because of the lack of data needed to estimate the
number of first admissions to these forms of correctional supervision.
2. Estimates of the number of first admissions are subject to sampling
and nonsampling errors. Because the numbers of first admissions are
based on a sample rather than a complete enumeration, the estimated
number of first admissions may vary depending on the size of the
estimate and the base population for each demographic group.
Nonsampling error can be attributed to many sources, such as
nonresponse, differences in interpretation of questions, recall
difficulties, and processing errors. Among inmates, the number of first
admissions may be slightly overestimated because of underreporting of
criminal histories. The full extent of nonsampling error is unknown.
3. No comparable inmate survey was conducted prior 1974 to enable the
calculation of first incarceration rates prior to this date. First
incarceration rates in 1970 and earlier were estimated to be 80% of
each age-specific rate of first incarceration in 1974.
If first incarceration rates in 1970 and earlier had averaged 90% of
each age-specific first incarceration rate in 1974, the estimated
number of adults alive in 2001 who had ever gone to prison would have
been 1.9% higher (5,723,000). Alternatively, if earlier first
incarceration rates had averaged 70% of 1974 rates, the estimated
number of persons ever to have been incarcerated in 2001 would have
been-1.9% lower (5,513,000).
4. Mortality rate schedules for prisoners were not available. Compared
with the general population, mortality rates for prisoners were
estimated to be 20% higher for adults under age 65, and the same for
those age 65 and older. The estimate was based on the lower overall
educational attainment of prisoners, and longitudinal studies
documenting the relationship between mortality and educational
attainment.
If mortality rates for adults ever incarcerated, under age 65 were
instead 40% higher than that of the general population, the estimated
prevalence of ever having gone to prison in 2001 would be 5,567,000
(-0.9% less). If mortality rates for prisoners had been equal to that
of the general population, the estimated prevalence would have been
0.9% higher in 2001 (5,670,000).
5. Comparable mortality rates prior to 1976 were not available.
However, there is minimal effect of declining mortality rates since
1900 on the estimated number of persons ever incarcerated. Prevalence
rates are only affected to the extent that there may have been a
different decline in mortality among those ever incarcerated (the
numerator) compared with all surviving members of a birth cohort (the
denominator). Furthermore, prevalence rates were applied to estimates
of the U.S. resident population (which fully reflect declines in
mortality).
6. Age-specific incarceration rates do not incorporate a forecast of
future rates of imprisonment, which may be affected by changes in
criminal behavior, law enforcement, and in sentencing policies.
Consequently, the lifetime likelihood of incarceration, 2001, and
projected prevalence rates for 2002 and beyond may be different.
A fuller description of the methodological techniques used in preparing
this report is available upon request from the author.
----------------------------------------------------------------------
The Bureau of Justice Statistics is the statistical agency of the U.S.
Department of Justice. Lawrence A. Greenfeld is director. BJS Special
Reports address a specific topic in depth from one or many data sets
that cover many topics.
Thomas P. Bonczar wrote this report, under the supervision of Allen J.
Beck. Tom Hester and Carolyn C. Williams edited the report. Jayne E.
Robinson administered final production.