The Intercensal Population Estimates and Projections Program

1
The Intercensal Population Estimates and
Projections Program

• Signe I. Wetrogan
• Assistant Chief for Population Estimates and
  Projections
• Presented to Metropolitan Washington Council of
  Governments
• Washington, DC
• June 7, 2005

2
Intercensal Estimates Program
Required under Title 13, Section 181 - US
Code During the intervals between each census of
populationthe Secretary, to the extent feasible,
should annually produce and publish for each
state, county, and local unit of general purpose
government which has a population of 50,000 or
more, current data on total population and
population characteristics, and to the extent
feasible, shall biennially produce and publish
for other local units of general purpose
government current data on total population.
3
Population Estimates

• National population estimates
• Monthly by age, sex, race, and Hispanic origin
• State population estimates
• Annually by age, sex, race, and Hispanic origin
• County population estimates
• Annually by age, sex, race, and Hispanic origin
• Functioning governmental units
• Annually by total population for 39,000
  governmental entities
• School Districts
• Annually by total population

4
Housing Unit Estimates

• State Estimates of Housing Units
• Annually
• County Estimates of Housing Units
• Annually

5
Population Projections

• National Projections
• Current Interim projections age, sex,
  selected race/Hispanic
• Origin groups
• Periodically prepared
• State Projections
• Current interim projections age and sex
• Periodically prepared

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Uses of Population Estimates

• Allocation of over 200 billion in federal funds
• annually
• Controls for federal surveys
• Current Population Survey
• American Community Survey
• Denominators for statistical rates
• Birth and death rates
• Per capita income
• Number of Senate clerk hires
• Program planning
• Location of public and private services

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Methodology
National, state, and county levels Component
method P2 P1 B - D NM
Subcounty level Distributive housing unit
method County population distributed to
subcounty parts based on updated estimates of
housing units
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All Estimates Must Be Consistent
County Pop. Total (Component Method)
U.S. Pop. Total (Cohort-Component Method)
Controlled To
Controlled County Pop. Total
State Pop. Total
Totaled To
Distributed To
Sub-County Pop. Total (Distributive Housing Unit
Method)
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National Methodology
National Methodology P2 P1 B - D
NM Beginning Population Census 2000 as
enumerated Births and Deaths Registered births
and deaths with demographic characteristics
from National Center for Health
Statistics (Receive micro records)
P2 P1 B - D NM Subcounty
level Distributive housing unit method County
population distributed to subcounty parts based
on updated estimates of housing units
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National Methodology
International Migration Net movement of the
foreign-born population

Developed from annual change in foreign-born
population as measured by the American Community
Survey (ACS) Net movement between the US and
Puerto Rico Measured by the Census 2000
Emigration of native-born population Measured by
the Census 2000
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State/County Methodology
Administrative Records Component of population
change method P2 P1 B - D
NM Done in cooperation with Federal State
Cooperative Program for Population Estimates
(FSCPE)
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The Federal-State Cooperative Program for
Population Estimates (FSCPE)
In 1973 the Federal-State Cooperative Program for
Population Estimates was formalized. The FSCPE
was formed to

• Promote cooperation between states and the
  Census Bureau
• Prepare a set of consistent county and subcounty
  estimates
• Improve and advance estimates methodology
• Enhance the recognition of local demographic
  work

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The Federal-State Cooperative Program for
Population Estimates (FSCPE)
District of Columbia contact Mr. Robert
BeaslyData Services DivisionD.C. Office of
Planning Maryland contact Mr. Hal Sommers Vital
Statistics AdministrationDept. of Health and
Mental Hygiene Virginia contact Dr. Julie Martin
Cooper Center for Public ServiceUniversity of
Virginia
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State and County Component Method
Births and deaths (NCHS, FSCPE )
Population (Census 2000)
International Migration (ACS, Census 2000)
Internal Migration (IRS)
Internal Migration (SSA NUMIDENT)
Medicare (CMS)
Group Quarters Updates (FSCPE)
State and County Estimating System
Dissemination Products
Monthly Survey Controls
Denominators
Media and Government Briefing Tables
Analytical Tables
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Estimates of County HH Pop Under 65
HHPHousehold Population NINatural
Increase NMIGNet Domestic Migration NETMOVENet
Movement from Abroad
HHP2
NI
NMIG
NETMOVE
- AGE
HHP1
Persons Aging from age 64 to age 65
Net movement of Foreign-born population
Last years estimate
Emigration
Tax return based rate
FSCPE
Net movement between US and Puerto Rico
NCHS
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Natural Increase

• Births and Deaths
• National Center for Health Statistics (NCHS)
• Data provided by State FSCPE representative

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Net Movement from Abroad

• Distribution of total US estimates to
  states/counties
• Distribute total US estimates of net movement of
  foreign-born
• Use Census 2000 state/county distribution of
  foreign-born, noncitizens, who entered the US in
  the last 5 years
• Distribute total US estimates of net movement to
  and from Puerto Rico
• Use Census 2000 state/county distribution of
  population who entered the US from Puerto Rico
  in last 5 years
• Distribute total US estimate of emigration of
  native-born population
• Use Census 2000 distribution of population

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Development of Net Migration for Population Under
age 65 - Overview of Annual IRS File

• Receive file in October of each year
• Contents used in migration processing
• Address, including ZIP code 4
• Address as of when the return was filed
• Number of exemptions by status
• Number of dependents by status
• SSN of filer and dependents
• Name on tax return

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Initial Processing of IRS Data Files

• Match records from prior year file to current
  year file using filers modified SSN
• Drop records that
• Do not match
• Filer must have returns for two consecutive years
• Have deceased in name field
• Assume address on tax file is residence of tax
  filer and exemptions

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Initial Processing

• Geocode records to state/county
• Use zipcode 4 to state/county coding guide
• Compare geocodes for matched returns
• If geocodes in time 1 and time 2 are different,
  the filer and exemptions on the return have
  migrated
• Have county of residence in year 1
• Have county of residence in year 2
• If geocodes in time 1 and time 2 are same, the
  filer and exemptions on the return are
  nonmigrants
• Under age 65 exemptions are used

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Calculate Net Migration Rate

• Tabulate for each county
• Outmigrants
• Number of under age 65 exemptions there in year
  1 and in different county in year 2
• Inmigrants
• Number of under age 65 exemptions there in year
  2 and in different county in year 1
• Nonmigrants
• Number of under age 65 exemptions there in year
  1 and year 2

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Calculate Net Migration Rate

• Net migration rate
• In-migrants out-migrants /
• non-migrants out-migrants

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IRS Data Confidentiality

• Title 26 protects the confidentiality of IRS
  data
• No individual record data can be released
• Any publicly released data must go through
  suppression
• SSNs are modified
• Internal access to IRS is severely restricted

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Develop Internal Migration Estimates for the
Household Population

• The net migration rate (derived from IRS data) is
  then applied to the household population under
  age 65
• This results in an estimate of net internal
  migration for the population under age 65
• Similar estimates are developed for the
  population over age 65 derived from Medicare data

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Estimates of Group Quarters Population

• Change in Group Quarters population is tracked
  through
• an annual report prepared by the FSCPE
• Additional data are collected from the DOD and
  the VA
• This change is applied to the Census 2000 GQ
  count

Types Institutional Correctional
Facilities Juvenile Facilities Nursing
Homes Other Non- Institutional Colleges
Universities Military Quarters Other
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State and County Component Method
COUNTY TOTAL POPULATION HHP0 lt65 HHP65 GQ

• Control this population to the National estimate
• Sum the controlled county population for each
  state
• Distribute the controlled county population to
  the
• subcounty level

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Subcounty Distributive Housing Method
Housing Units and Population (Census 2000)
Building Permits (Census)
BAS Data (Census)
Vacancy/ PPH (Census 2000)
Group Quarters Updates (FSCPE)
Special Census Outputs
County Population Estimates (State/County System)
Subcounty Estimating System
Dissemination Products
HUD Funds Allocation
MSA Designation Updates
Media and Government Briefing Tables
Analytical Tables
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Place and County Subdivision Population Estimates

• Distributive Housing Unit Method

• Change in Housing Units since the last Census at
  the subcounty level is used to distribute the
  estimated county population

• Components of Housing Unit Change
• Residential Construction
• Mobile Home Placements
• Housing Unit Loss

• Subcounty Group Quarters data are taken from the
  same source as county Group Quarters data

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Housing Unit Estimates Equation

• HU2 HU1 (NC NM) - HL
• HU Housing Units
• NC Estimated New Residential Construction
• NM Estimated New Residential Mobile Home
  Placements
• HL Estimated Residential Housing Loss

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Estimated Residential Construction

• Building permits
• Compiled by the Census Bureaus Manufacturing and
  Construction Division (MCD)

• Nonpermitted construction
• Estimated from Annual Survey of Construction and
  Census 2000 data

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Mobile Home Placements

• State mobile home shipment data distributed to
  subcounty areas based on the subcounty areas
  share of states mobile homes
• Mobile home data are no longer a 100 Census item

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Housing Unit Loss

• Based on data from 1997-2003 American Housing
  Survey (AHS)
• 3 types of noninterviews
• Interior exposed to the elements
• Demolished or disaster loss
• House or mobile home moved
• Housing unit loss rates developed based on
• Structure type
• Age of structure

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Subcounty Distributive Housing Unit Method
Subcounty Housing Units Residential
Construction Mobile Home Placements - Housing
Unit Loss

• Use each subcounty areas HU based household
  population
• estimate to distribute the county household
  population
• Household population (HU vacants) PPH
• Vacants Census 2000 rate
• PPH Census 2000 persons per occupied housing
  unit
• Add the Group Quarters Population

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Population Projections Methodology
National and state -Component method
P2 P1 B - D NM Projections - not
forecasts Outcomes of mathematical model Assume
recent demographic trends continue
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Further Information

• Population Estimates Web Site
• http//www.census.gov/popest/estimates.php
• Population Projections Web Site
• http//www.census.gov/population/www/projections/p
  opproj.html
• Signe Wetrogan
• Assistant Chief for Population Estimates and
  Projections
• Signe.I.Wetrogan_at_census.gov
• [phone]