U.S. Department of Justice
Office of Justice Programs
Bureau of Justice Statistics
Bulletin

Jail Inmates at Midyear 2007
June 2008, NCJ 221945
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tables. A Zip archive of the tables in this report in 
spreadsheet format (.csv) and the full report including 
tables and graphics in .pdf format are available from:
http://www.ojp.usdoj.gov/bjs/abstract/jim07.htm

This report is one in a series. More recent editions may
be available. To view a list of all in the series go to
http://www.ojp.usdoj.gov/bjs/pubalp2.htm#pjmidyear

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William J. Sabol, Ph.D. 
and Todd D. Minton
BJS Statisticians

On June 29, 2007, the number of inmates held in local jails reached
780,581, an increase of 1.9% (or 14,571 inmates) since June 30, 2006
(figure 1). Between 2000 and 2007 the number of inmates confined in the
nation's jails increased at an average annual rate of 3.3%. With the
exception of 2005, the rate of growth in the jail inmate population has
declined every year since 2002. Growth slowed from 2.5% in 2006 to 1.9%
in 2007. The rate of growth in the 12 months ending June 29, 2007 was the
smallest annual growth rate in the jail population since 2001 and the second
smallest since 1981. 

The midyear count of inmates does not fully represent the total jail
population throughout the year. Jail populations rise (admissions) and fall
(releases) day-to-day. These fluctuations are taken into account in the 
average daily population. From midyear 2006 to midyear 2007, the average 
daily jail population increased 2.4%, from 755,896 to 773,800 (appendix 
table 4). From midyear 2006 to midyear 2007, the rate of growth slowed 
for both the average daily jail population and the count of jail inmates.

Jail capacity and population increase at the same rate during 2007

The total rated capacity of local jails at midyear 2007 reached 813,502 beds,
up from an estimated 677,787 beds at midyear 2000 (figure 2). This was an
average increase of 2.6% per year. Rated capacity is the maximum number
of beds or inmates allocated to each jail facility by a state or local rating
official. 

Local jail officials added jail capacity at a rate about equal to the growth in
the number of inmates confined at midyear. During the 12-month period
ending June 29, 2007, the jail inmate population and rated capacity of the
nation's jails both increased 1.9%. In absolute numbers, inmates increased
by 14,571 and beds by an estimated 15,502. At midyear 2007, local jails
operated at 96% of rated capacity, up from 90% at midyear 2001.

Local jails admitted about 13 million persons during the 12 months ending
June 29, 2007

The jail population at midyear 2007 represented a comparatively small
percentage of all admissions reported over the 12-month period. Local jails
admitted an estimated 13 million persons during the 12 months ending June
29, 2007, or about 17 times the size of the inmate population (780,581) at
midyear.***See Methodology for methods used to estimate admissions. See
1999 Census of Jails (NCJ 186633) and Jail and Jail Inmates 1993-94, BJS
Bulletin (NCJ 151651) for data used to estimate admissions.*** In 1999,
there were an estimated 11.4 million admissions during the 12 months
ending June 30, about 19 times the size of the June 30 population of
605,943 inmates. An estimated 9.8 million inmates were admitted to local
jails during the 12 months ending June 30,1993, about 21 times the number
of inmates held in the nation's jails (459,804) at midyear. 

Number of small jail jurisdictions declined; large jail jurisdictions increased

Based on data from the 1999 Census of Jails and the 2005 Census of Jail
Inmates, the number of jail jurisdictions nationwide declined by 123, from
2,999 to 2,876 jurisdictions (table 1). Jurisdictions reporting an average
daily jail population of 50 or fewer inmates (small jails) decreased by 371,
from 1,518 to 1,147. These jail jurisdictions accounted for all of the decline
in the number of jurisdictions during this period. Over two-thirds (248) of
the small jail jurisdictions grew into a larger size category, and the
remaining 123 closed between 1999 and 2005. The number of jurisdictions
in all other size categories (measured by the average daily population)
increased during the period.

Based on the number of large jail jurisdictions in the 2005 Census of Jail
Inmates, a comparison of the same 159 jail jurisdictions was conducted for
the 1999 Census of Jails. A total of 120 of the 158 (one jurisdiction was 
not in the 1999 Census) jail jurisdictions met the definition of a large jail 
jurisdiction in both 1999 and 2005 (table 2). 

These jurisdictions accounted for the largest change in the number of
inmates (32,204). In comparison, 38 jail jurisdictions that had less than
1,000 inmates in 1999 moved into the large category at midyear 2005. These
jurisdictions experienced the largest percent change in the inmate 
population (71.3%). 

Admissions to large jail jurisdictions fluctuated throughout the year

In 2004 BJS conducted the Survey of Large Jails (SLJ), an addendum to the
Annual Survey of Jails. The survey gathered, among other items, monthly
admissions in 146 jurisdictions with average daily populations of 1,000 or
more inmates in 2004. Based on 129 complete responses for admission data,
these large jurisdictions reported an average daily population of 285,452
inmates. They reported nearly 4.5 million admissions to their facilities from
January 2003 to January 2004 (figure 3). Monthly admissions fluctuated
from a low of 308,582 in February 2003 to a high of 357,259 in August
2003. (See Methodology for additional information on the Survey of Large
Jails.)

Jail population growth concentrated in large jails

At midyear 2007, jail jurisdictions (173) with an average daily jail
population of 1,000 or more inmates accounted for about 6% of all jail
jurisdictions and about 52% of the jail inmate population (figure 4). In
comparison, jail jurisdictions with an average daily population of fewer than
50 inmates accounted for nearly 40% of all jail jurisdictions and less than
3% of the nation's jail population.

Between midyear 2000 and midyear 2007, the number of inmates held in
local jails increased by nearly 26% (or 159,433 inmates), from 621,148 to
780,581 (table 3). The number of inmates confined in large jail jurisdictions
grew by nearly 33% between midyear 2000 and 2007 and accounted for
62% of the total growth in the jail population. Inmates confined in
jurisdictions with an average daily population between 500 to 999 grew by
nearly 31%. The number of inmates held in small jail jurisdictions declined
by 23%.

More than 4 in 10 (43%) admissions during the last week of June 2007 were
to large jail jurisdictions (table 4). Small jail jurisdictions holding fewer
than 50 inmates accounted for 5.3% of all jail admissions. They experienced
a higher turnover rate (110.5%) than large jail jurisdictions. The turnover
rate takes into account all admissions into and releases from jails. Higher
turnover rates mean relatively larger numbers of admissions and releases
relative to the size of the average daily population.

At midyear 2007, 96% of jail capacity was occupied

Larger jail jurisdictions generally had a higher percent of capacity occupied
than small jail jurisdictions at midyear 2007. Jurisdictions with an average
daily population of 500 or more inmates were operating at about 99% of
rated capacity, compared to 65% of rated capacity for jail jurisdictions with
average daily populations of fewer than 50 inmates.

Jurisdiction size*       Population at midyear 2007,
                         as a percent of capacity   
     
     Total                       96.0%  
Fewer than 50 inmates            64.5        
50 to 99                         84.6        
100 to 249                       92.4          
250 to 499                       97.8          
500 to 999                       99.3          
1,000 or more                    99.5  
     
*Based on the average daily population.                

About 29% of the nation's jail population was held in the 50 largest local
jail jurisdictions at midyear

At midyear 2007, the 50 largest jail jurisdictions held about 29% (or
227,901 inmates) of the nation's jail population (table 5). Collectively, these
jurisdictions had an average daily population of 227,626 inmates and were
operating at about 94% of rated capacity at midyear 2007, unchanged from
midyear 2006. 

Characteristics of jail inmates at midyear 2007

*Since midyear 2000, the percentages of men and women  in local jails has
remained relatively unchanged (table 6). 

*The number of women in local jails reached 100,047 in 2007, up from
70,414 in 2000 (appendix table 4).

*Nearly 6 in 10 offenders in local jails were racial or ethnic minorities at
midyear 2007. An estimated 301,900 were black and 125,600 were Hispanic
or Latino.

*The percentages of whites and blacks confined in jail remained relatively
unchanged since midyear 2006; the Hispanic or Latino population grew from
15.6% at midyear 2006 to 16.1% of all inmates midyear 2007.

*At midyear 2007, 62% of inmates had not been convicted or were awaiting
trial, up from 56% in 2000.

*At midyear 2007, the jail incarceration rate was 259 inmates per 100,000
U.S. residents, up from 226 per 100,000 residents in 2000 (appendix table 4).

Jail inmates who were non-U.S. citizens or held for U.S. Immigration and
Customs Enforcement

*Most jail jurisdictions (84%) reported whether the jail population included
non-U.S. citizens (table 7).  
 
*Based on jurisdictions that reported housing non-U.S. citizens, non-U.S.
citizens accounted for nearly 8% of the jail population at midyear 2007, up
from 7% in 2006 and 5.4% in 1999.

*The majority of jail jurisdictions were able to report whether inmates were
being held for U.S Immigration and Customs Enforcement (table 8).

*The percentage (2.2%) of inmates held for U.S. Immigration and Customs
Enforcement at midyear 2007 has remained relatively unchanged since 2002.

Methodology

Annual Survey of Jails

In each year between the years that BJS conducts a complete census of local
jails, BJS conducts the Annual Survey of Jails (ASJ). ASJ is a sample survey
of local jails used to estimate the number and characteristics of local inmates
nationwide. For the 2007 ASJ, the U.S. Census Bureau, as the collection
agent, drew a sample of 874 jurisdictions and 936 jail facilities. Local jail
jurisdictions included counties (parishes in Louisiana) or municipal
governments that administer one or more local jails. 

The 2007 ASJ sample included all jails with certainty (63) that were operated
jointly by two or more jurisdictions, or multi-jurisdictional jails. Other jail
jurisdictions included with certainty (269) were those that--

*held juvenile inmates at the time of the 2005 Census of Jail Inmates and had
an average daily population of 500 or more inmates during the 12 months
ending June 30, 2005
*
held only adult inmates and had an average daily population of 750 or more.

The remaining jurisdictions were stratified into two groups: jurisdictions
with jails holding at least one juvenile on June 30, 2005, and jails holding
only adults on that date. Using stratified random sampling, 542 jurisdictions
were selected from 8 strata based on the two conditions enumerated above
and 4 strata based on the average daily jail inmate population during 2005.
The average daily jail inmate population was derived from the 2005 Census
of Jail Inmates.

Data were obtained from sampled jurisdictions by mail-out and web-based
survey questionnaires. After follow-up phone calls to respondents, the
response rate for the survey was 100% for critical items, such as the number
of inmates confined, average daily population, and rated capacity. (See
appendix tables 6, 7 and 8 for standard errors associated with reported
estimates from the ASJ 2007 at <http://www.ojp.usdoj.gov/bjs/pub/pdf/jim07.pdf>.)

Survey of Large Jails

In 2003 BJS worked with the National Institute of Correction's Large Jail
Network to identify the areas where additional data were needed to guide
decision-making on jail policies and programs. As a result of this
collaboration, BJS developed the 2004 Survey of Large Jails (SLJ), an
addendum to the Annual Survey of Jails that gathered information from jail
jurisdictions with an average daily population of 1,000 or more inmates or a
rated capacity of 1,000 or more beds. 

The survey focused on critical issues related to jail operations and inmate
management, information on offender flows through local jails,
corresponding workloads, and jail programs and treatment. Specifically, the
survey measured the number of jail admissions, including conviction status,
most serious offenses, and screening at intake for mental health disorders,
risk of suicide, and drug use. It also included questions on the number of
inmates participating in counseling and special programs, number of inmates
discharged, types of releases, and lengths of stay.

Data were obtained by mailed questionnaires. Through 
follow-up phone calls and facsimiles, 131 of the 146 jail jurisdictions (90%)
responded.

Weekly admission and release estimation procedures

Based on the 2007 ASJ, 830 of the 936 jail facilities (89%) provided valid
data on weekly admissions and releases. Because there were nonresponse and
incomplete data on admissions and releases, data on offender flows through
local jails were estimated for 106 jail facilities to calculate a weekly estimate.
Estimates were based on two criteria: 

*Data for 73 jail facilities included admission and release data based on the
response to the 2006 Annual Survey of Jails.

*Data for 33 jail facilities were based on the average number of admissions
and releases for the average daily population category in which the facility
was grouped.

Calculating annual admissions 

Based on findings from the 2004 Survey of Large Jails (SLJ), BJS
determined that the June admission data were a reliable source to calculate a
nationwide annual admission estimate. Although the number of admissions
to jails fluctuated throughout the year, the SLJ tracked monthly movements
from January 2003 to January 2004 and determined that the June 2003 count
(339,500) closely matched the annual average number of admissions (342,956). 

The number of annual admissions was calculated by multiplying the weekly
admissions by the sum of 365 days divided by 7 days. 

Calculating weekly turnover rates

Weekly jail turnover rates were modeled after the Bureau of Labor Statistics'
Job Openings and Labor Turnover Survey. Additional information on
turnover rates is available at <http://www.bls.gov/jlt/>. Jail turnover rates
were calculated by adding admissions and releases and dividing by the
average daily population. The turnover rate takes into account admissions
into and releases from jails and gives an indication of the volatility of the jail
population. Higher turnover rates mean relatively larger numbers of
admissions and releases relative to the size of the average daily population. 

This report in portable document format (includes 8 appendix
tables) and in ASCII and its related statistical data are available at the BJS
World Wide Web Internet site: <http://www.ojp.usdoj.gov/bjs/abstract/jim07.htm>

Office of Justice Programs
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The Bureau of Justice Statistics is the statistical agency of
the U.S. Department of Justice. Jeffrey L. Sedgwick is the
director.

BJS Bulletins present the first release of findings from
permanent data collection programs.

This Bulletin was written by William J. Sabol, Ph.D., and
Todd D. Minton. Heather Couture verified the report. 

Lisa A. McNelis carried out the data collection and
processing with assistance provided by Elizabeth Aguilar,
Nicole Adolph, Andrea Arroyo, Adam Bacon, Greta Clark,
Shannon Clerkin-James, and Garry Smith under the supervision
of Charlene M. Sebold, Governments Division, Census Bureau,
U.S.Department of Commerce. Duane H. Cavanaugh and Diron J.
Gaskins provided technical assistance.

Georgette Walsh edited the report, Tina Dorsey produced the
report, and Jayne E. Robinson prepared the report for final
printing under the supervision of Doris J. James.

June 2008, NCJ 221945

6/04/2008/JR