Understanding Sources of Differences from Interagency Research:

ACS-GQ and BJS Correctional Population Estimates

FCSM Statistical Policy SeminarDecember 4, 2012

William J. SabolBureau of Justice Statistics

Motivation: Census report from 2006 ACS on correctional populations

• September 2007: Census report from the 2006 ACS • Census’ “first in depth look at people in prisons [sic]

since the 1980 Census.” (Washington Post)• Census reported the 2006 correctional population at

2.1 million and reported a 4% change in the corr. pop. since 2000.

• Census figures differed from BJS, which reported more than 2.3 million in prison or jail.

Motivation: Responses to Census report

• Pew Foundation: Letter to editor of WP; claimed the Census report gave a false impression about the growth of correctional populations, which they had forecast to increase more rapidly than implied by the Census numbers; pointed out that Census’ counts were lower than BJS counts.

• BJS: I wondered why the ACS had not coordinated its release with BJS or perhaps why it had not attempted to reconcile its statistics with BJS (then) twice-yearly releases, especially since the Governments Division collected the prison & jail count data for BJS.

Nature of discrepancies

• Estimates of inmates in correctional facilities– ACS: 2.1 million inmates in correctional facilities in 2006– BJS: 2.3 million

• Change estimates– ACS: 4% increase from 2000-2006– BJS: 15% increase from 2000-2006

• Characteristics of inmates– Age, race– Education, veterans’ status, disability

• Estimates tied to key policy issues in sentencing and corrections

Differences between BJS and ACS-GQ correctional population estimates have diminished over time…

Decrease in differences arises from different trends

BJS methods

• Establishment surveys of all 51 departments of corrections

• Establishment survey of sample of all local jails• Reference date is yearend (ACS is continuous

collection)

Estimates inform to key sentencing & corrections policy issues

• Size and cost of corrections—efforts to reduce the size of the prison population while not harming public safety and to repurpose funds for other uses;

• Fairness and equity of sentencing—racial composition and disparities in punishment; long-standing issues in sentencing & corrections

• Re-integration (re-entry) of former inmates—specific needs (e.g., education & employment), specific groups (e.g., veterans and persons with disabilities)

• Utility of ACS-GQ—potential source for ongoing, routine estimates of key indicators of composition of national and state-level correction population.

Comparable age distributions in 2006

Comparable age distributions in 2009; BJS age data from administrative records and self-report survey

BJS and ACS-GQ differences on race revolve around percent black and persons of 2 or more races

BJS estimates for non-Hispanic blacks may differ from ACS-GQ due to the number of persons of two or more races in its surveys. BJS adjusts establishment survey data on race by self-report inmate survey estimates.

Differences in racial composition has implications for measures of racial disparity

Black-to-white racial disparity ratio (ratio of incarceration rates) is lower with ACS-GQ estimates; no major differences for Hispanics.

ACS-GQ and BJS: Educational attainment questions

ACS-GQ• What is the highest degree

or level of school you have completed? [Mark one box. If currently enrolled, mark the previous grade or highest degree received.]

BJS inmate survey• Before your admission, what

was the highest grade of school that you ever attended?

• Did you complete that year?• Do you have a GED, that is, a

high school equivalency certificate?

• Did you earn your GED while serving time in a prison, jail, or other correctional facility?

13

Census staff (Ewert & Widlhagen, 2011) have compared ACS and BJS inmate surveys but limited comparison of differences primarily to differences in question wording rather than reconciling differences.

ACS-GQ and BJS inmate surveys: Prisoners have high rates of HS non-completion

14

Source: U.S. Census Bureau, American Community Survey, 2009; Bureau of Justice Statistics, Survey of Inmates in State Correctional Facilities, 2004

ACS-GQ and BJS: School enrollment questions

ACS• At any time IN THE LAST 3

MONTHS, have you attended school or college? [Include… [school] which leads to a high school diploma or a college degree.

• What grade or level were you attending?

BJS inmate survey• Since your admission, have

you ever been in any other education program? Exclude vocational training.

• What kind of program was that...?

15

BJS inmate survey shows higher rates of enrollment

16

Source: U.S. Census Bureau, American Community Survey, 2009; Bureau of Justice Statistics, Survey of Inmates in State Correctional Facilities, 2004

ACS-GQ and BJS: Veterans

ACS-GQ:• Have you ever served on active

duty in the U.S. Armed Forces, military reserves or National Guard?

• When did you serve on active duty in the U.S. Armed Forces? [Mark (x) a box for each period served.]

• Do you have a VA service-connected disability rating?

• What is your service-connected disability rating?

BJS inmate surveys:• Did you ever serve in the U.S. Armed

Forces?• In what branch(es) of the Armed

Forces did you serve?• When did you first enter the Armed

Forces?• During this time did you see combat

in a combat or line unit?• When were you last discharged?• Altogether, how much time did you

serve in the Armed Forces?• What type of discharge did you

receive?ACS’ VA service-connected disability questions; potentially high-value for VA medical services planning and programs for criminal justice involved veterans.

NSDUH: Veterans questions

BJS: Percent of state/federal prisoners reporting prior military service

Veteran status of criminal justice populations, various surveys, 2007

BJS estimates from inmates surveys (prisons & jails). Item allocation (veteran status) on the order of 10% in ACS; increasing over time; BJS missing on veteran status on the order 2-3%.

Trends in ACS-GQ estimates of veterans in adult correctional facilities diverge from NSDUH estimates

VA medical services: Planning for criminal justice system involved veterans; requesting from BJS annual estimates of veterans under correctional supervision; BJS & VA initiating efforts to determine feasibility of matching BJS administrative records with VA data to identify veterans incarcerated.

ACS-GQ and BJS: Hearing and vision disability

ACS-GQ:• Are you deaf or do you have

a serious hearing difficulty?• Are you blind or do you

have serious difficulty seeing even when wearing glasses?

BJS inmate surveys:• Do you have difficulty

seeing ordinary newsprint, even when wearing glasses?

• Do you have difficulty hearing a normal conversation, even when wearing a hearing aid?

ACS-GQ and BJS: Cognitive

ACS-GG:• Because of a physical,

mental, or emotional condition, do you have serious difficulty concentrating, remembering, or making decisions?

BJS inmate survey:• Does a mental health

condition keep you from participating fully in work, school, or other activities?

• Do you have a learning disability, such as dyslexia or attention deficit disorder?

ACS-GQ and BJS: Ambulatory, self-care, independent living

ACS-GG:• Do you have serious

difficulty walking or climbing stairs?

• Do you have difficulty dressing or bathing?

• Because of a physical, mental, or emotional condition, do you have difficulty doing errands alone such as visiting a doctor’s office or shopping?

BJS inmate survey:• Do you use a cane,

wheelchair, walker, hearing aid, or other aids to help you with your daily activities?

BJS and ACS-GQ differ on most measures of disability status

ACS-GQ, 2008-2010 (3-yr data) BJS inmate survey

Federal prisons/detenti

on

State prisoners

Federal prisoners

State prisoners

With a disability 19.0 25.7 23.4 34.3

Hearing 4.0 4.9 5.0 7.0

Vision 4.9 6.2 8.6 10.3

Mobility 7.2 10.2 2.3 2.5

Differences in items; BJS mobility questions differ from ACS mobility questions.

BJS-Census project to identify and measure sources of discrepancies

• Definitional differences• Frame & sampling

– Match BJS prison & jail frames to ACS frame, 2010 decennial– Large GQ populations and sampling (improvement over time in expected populations in large GQs)

• Weighting & estimation– Impact of Census Population Estimate Program control totals

• Instruments– Variation in common questions– BJS’ surveys cover domains not in ACS (mental health, medical problems substance abuse, offenses & criminal

history, criminal justice status, etc.)• Mode of collection

– Self-report surveys, CAPI vs. ACASI– Establishment surveys– Administrative records

• Reporting – Prisons vs. jails vs. total correctional population– Classification differences

• Documentation– Report on what is learned and what can be done to address discrepancies

BJS-Census effort to assess sources of differences between ACS-GQ and BJS estimates

Effort related to issues arising in 2007 NAS report on the ACS

Recommendations from the 2007 NAS report on the ACS

Comments from the 2007 NAS report :

• Census Bureau should give serious consideration to whether the long-form-sample type data from the continuous ACS for the institutional population…is needed to an extent that justifies the costs.

• Work with user community to identify items to collect every year and items that are not needed or for which data are not likely to be of sufficient quality to be useful– For example, utility of asking prisoners about income; quality of data on

prisoner income [NAS reported that in 2000, 78%...of prisoners…had all of their income imputed because they did not answer any of the income questions; by comparison 25% of household residents had all of their income imputed.

• Additional item of high utility: Date of entry into facility.

Definitional issues: ACS Group Quarters

• Place where people live or stay, in a group living arrangement, that is owned or managed by an entity or organization providing housing or services for the residents.

• Include places such as college dormitories & residence halls, residential treatment centers, skilled nursing facilities, group homes, military barracks, correctional facilities, and workers’ dormitories.

Definitions: ACS-GQ correctional facilities for adults

• Correctional residential facilities: Community-based facilities operated for correctional purposes; include halfway houses, restitution centers, prerelease, work release, study centers.

• Federal detention centers: Provide short-term confinement for adults pending adjudication or sentencing

• Federal & state prisons: Places where persons convicted of crimes serve their sentences, such as prisons, penitentiaries, correctional institutions

• Local jails/municipal confinement facilities: Operated for counties, cities, and American Indians/Alaska Natives; hold adults pending adjudication/sentencing.

Definition: BJS correctional populations

• Prisons: Include prisons, penitentiaries, and correctional institutions; boot camps, prison farms, reception, diagnostic and classification centers; release centers, halfway houses; road, conservation, forestry camps operated for prisoners; vocational training; prison hospitals, and treatment facilities for prisoners. [Some overlap with ACS-GQ residential correctional facilities.]

• Local jail facilities: Confinement facilities, which are usually administered by a local (county/city) law enforcement agency that are primarily intended for adults but sometimes hold juveniles before or after adjudication. Primarily receive and hold individuals pending arraignment, awaiting trial, conviction, or sentencing; may hold inmates sentenced to short terms or in some cases to longer terms to alleviate crowding in state prisons. Some jail facilities operate community-based programs as alternatives to incarceration.

Definitional differences

• BJS and ACS-GQ definitions of adult correctional facilities generally comport with each other

• Some differences in classification:– BJS includes some types of ACS-GQ correctional residential

facilities as prison facilities– ACS-GQ includes federal detention centers; BJS does not

include these in its annual counts of prisoners• Counting/classification differences would generally lead

to the expectation that BJS counts would be lower than ACS-GQ estimates (due to BJS exclusion of some CBCF and federal detention centers).

Frame and sampling

• ACS frames: Current (from 2006) and 2010 decennial; proceeds from 2010 decennial not fully incorporated into ACS

• ACS improves GQ frame by annually updating the expected population for GQs, especially large GQs.– Between 2006-08, mean difference between expected and observed population in GQs

with populations greater than 400 persons declined from a 5.8% (mean difference) to a 1.7% (mean difference). Mean absolute difference also declined from 30% to 14% (Source: Beaghen and Stern (2009))

• BJS: – Current: 2010 prison & jail facility frames– In progress: 2012 prison facility census– Planned: 2014 jail census

• Match frames– Identify common/unique facilities– Compare populations, especially in large GQs

Frame (as described in the 2007 NAS report):

Note: The Internet searching for new prisons is one particular issue that has given rise to the current BJS-Census project on the ACS-GQ/BJS estimates.

2010 Decennial Census counts line up with BJS counts fairly well

• 2010 decennial census counts of the correctional population generally comport with BJS counts

• Major differences include:– State prisoners in 2010 decennial census is about 60,000

fewer than BJS’s count (1.31 mn. in BJS surveys; 1.25 in decennial (4.5%) low)

– Local jail inmates in 2010 decennial is low (682,000 vs. 749,000 in BJS (9% lower than BJS); but one-day counts of jail inmates fluctuates widely, and April 1st vs. June 30th counts could reflect normal variation.

• Federal prisoner counts are equivalent.

Sampling and weighting/estimation

• Sample selection; quality of ACS frame; coverage error, relative to BJS frame– ACS sampling: State by type of GQ stratification; within state type by geography;

corrections facilities identified by type (e.g., prisons, jails, etc.); classified into 2 (3) groups (large, small, unknown pop.); systematic sample of facilities based on groups of 10 persons; most prisons & jails fall into the “large GQ” category (hold > 15 persons).

• BJS: – Annual counts: Establishment surveys of all departments of corrections

(censuses of DOCs) and sample survey of jails– Inmate surveys: Two-stage sampling, (1) facilities proportionate to size

and (2) systematic sample of inmates (approx. 40 per facility); oversampling women; 4-states self-representative

• Control totals for ACS-GQ: PEP estimates of GQ populations

Instrumentation

• ACS-GQ: – Same form as ACS; allows for comparisons to household

population; – Concerns about relevancy of some items (e.g.,

employment in past week);• BJS: Instrument completes ACS instrument with

some overlap– Inmate survey covers 10 domains, most not in ACS

• Mode: ACS is primarily CAPI; BJS mode varies depending upon survey, including ACASI.

Instrumentation: Policy-relevant topics in ACS not annually covered by BJS surveys

• Frequently asked questions/topics of BJS:– Non-U.S. citizens and country of birth/origin– Welfare benefits– Insurance coverage, especially in relation to the Affordable

Care Act– Residence prior to incarceration; where prisoners should

be counted for purposes of the census• BJS asks where inmates lived prior to admission• ACS asks where inmates lived a year ago

Reporting

• ACS-GQ: – 1-year estimates report total correctional population; public

confusion that correctional populations = prisoners.– PUF shows institutional vs. noninstitutional GQ;– Census studies: report by type, e.g., prisons

• BJS:– Reports total correctional population but distinguishes

between types (prisons vs. jails), given different functions and population composition of these types

– Reports separately on inmates in prisons and jails from surveys

Reporting: Different functions and compositional differences between prisons and jails

• Prisons: Hold persons sentenced for felonies; mean time served of about 2 years (across all commitments), 3 years for those sentenced from the courts; about 650,000 commitments per year on a stock of about 1.5 million.

• Jails: Hold unconvicted persons primarily (2/3rds of the jail population); average stay is about 3 weeks; half spend two or fewer days in jail; 10-12 million bookings per year on a stock of about 750,000.

Useful enhancements to both agencies’ efforts

• ACS-GQ: – Use proceeds of the effort to assist in updating ACS-GQ

frame during inter-census periods– Ask a question about the date of entry into the GQ

• Useful for estimating length of stay and turnover in correctional facilities

• Important for issues related to prisoner reentry– Employment– Insurance coverage– Expectations about receipt of Federal benefits

– Produce estimates adjusted to BJS control totals

Useful enhancements to both agencies’ efforts

• BJS– Use decennial census on GQ in lieu of one of its censuses

(saving costs to taxpayers)– Modify inmate survey instruments to comport with ACS

and other national surveys (enhance comparability)– Use modified ACS-GQ estimates to provide policy makers

with relevant statistical information on prison & jail inmate populations

– Use multi-year ACS-GQ for state-level estimates of characteristics of prison & jail inmates

Importance of addressing discrepancies

• ACS-GQ data a valuable source of data on core indicators of characteristics of prison & jail inmates – BJS can use the ACS-GQ data for statistical reporting if BJS

and Census can identify, address and correct survey procedures

– Comparability: BJS’ own surveys of prison & jail inmates capture data in other domains and key estimates can be pegged to ACS-GQ

• Large sample sizes and reliable estimates; comparisons to noninstitutionalized populations

• Enhance utility of ACS-GQ data

Concluding thoughts

• Identifying discrepancies is the easy part; identifying the phases in a survey’s lifecycle to focus on is more difficult.

• Persistence required in identifying the key personnel to work with; interagency work is hard.

• Try to organize the work around achieving mutually-beneficial goals for each agency.

• Allow for learning to motivate changes.• Draw upon received wisdom.