Census Bureau’s Interim and Final State Projections Population Projections Branch Population Division U.S. Census Bureau

Interim State Population Projections

3Introduction Rationale for interim population projections Section outline  Methodology  Assumptions  Proposed products

4Methodology Cohort Component Method Project Births, Deaths, Internal Migration, and International Migration separately Basic Formula: P 1 = P 0 + B - D + IIM - IOM + NIM Where, P 0 = Base year population B = Projected births D = Projected deaths IIM = Projected internal in-migration IOM = Projected internal out-migration NIM = Projected net international migration

5Assumptions Fertility:  Fertility rates held constant, with adjustment to fit estimated births from 2001 to 2003 Mortality:  Mortality rates held constant, with adjustment to fit estimated deaths from 2001 to 2003 Internal migration:  Follow the IRS migration trends in region-to-state and state-to-region migration flows.  Hold the composition of census migration flows constant. International migration:  Follow the current international trends in states  Hold constant the composition of immigrant population in the state

6 Proposed Products Highlights (Press release) Summary tables with statistics such as median age, sex ratio, dependency ratio and graphs such as pyramids Detailed age, and sex for all states, year by year ( )

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Final State Population Projections

9Introduction Challenges to new projections  Data consistency issues between Census 2000 and previous censuses  Data consistency issues between census data and other data sources such as NCHS Section outline  Methodology  Input data  Assumptions  Proposed products

10Methodology Cohort Component Method Project Births, Deaths, Internal Migration, and International Migration separately Basic Formula: P 1 = P 0 + B - D + IIM - IOM + NIM Where, P 0 = Base year population B = Projected births D = Projected deaths IIM = Projected internal in-migration IOM = Projected internal out-migration NIM = Projected net international migration

11Methodology To project the demographic details, the formula should be expanded as follows: 1 P i,j,k = 0 P (i-1),j,k + B j,k - D i,j,k + IIM i,j,k - IOM i,j,k + NIM i,j,k Where, i = age ( and over) j = sex (male, female) k = race/Hispanic origin (White, Black, American Indian, Asian, Hawaiian, and multi-race by Hispanic origin, a total of 12 groups)

12 Input Data Starting point:  Census 2000 for base year and denominator of rates  Births 1999, 2000, 2001 for fertility rates  Deaths 1999, 2000, 2001 for mortality rates  Internal migration: IRS annual migration flows data: Census migration flows data:  Foreign born population entering U.S. :  Population estimates and component of change: 2001 to 2004 Age, sex, race, and Hispanic origin for all data items except IRS

13 Input Data Projection years:  Projected national fertility rates  Projected national survival rates  Projected IRS region-to-state and state-to-region migration rates  Projected national population  Projected national births  Projected national deaths  Projected national international migration  Change in state fertility rates:  Change in state survival rates:

14 Base Population Use modified Census 2000 race data (31 race combinations)  The “some other race group” was eliminated  Tabulate “Minimum and Maximum” race groups Convert Census 2000 race groups to 1990 race groups, using equal fraction assignment procedure State population estimates 2004

15 Fertility Input Data Births by age and race of mother from NCHS:  1989, 1990, 1991, 1999, 2000, and 2001 Bridged census 2000 female by race Age-specific fertility rates based on 1990 race only for 6 race groups  (1) Non-Hispanic total  (2) Non-Hispanic white  (3) Non-Hispanic black  (4) Non-Hispanic American Indian  (5) Non-Hispanic Asian and Pacific Islander  (6) Hispanic origin total

16 Mortality Input Data Deaths by age, sex, race and Hispanic origin  1989, 1990, 1991, 1999, 2000, and 2001 Census 2000 by single years of age (0 ~ 100+), sex, race, and Hispanic origin (Bridged race groups) Mortality rates by race and Hispanic origin  Same as fertility rates by race, only prepare 6 race / Hispanic groups and apply the mortality rates to appropriate race groups  Prepare complete life tables and survival rates Development of mortality changes by state ( )

17 Internal Migration Input Data IRS region-to-state and state-to-region annual migration flows (1975 – 2003 time series):  For projecting total internal migration into the future Census 2000 region-to-state and state-to-region migration flows between 1995 and 2000 by age, sex, race, and Hispanic origin  For projecting the composition of internal migration by age, sex, race, and Hispanic demographic detail, controlled to projected IRS migration flows Data issues about 2,550 state-to-state migration flows  Many small flows  Empty data cells by demographic detail

18 International Migration Input Data Estimates of net international migration rates by state Foreign-born population entering the U.S. by age, sex, race, and Hispanic origin, Projected national net international migration by age, sex, race and Hispanic origin

19Assumptions Fertility:  Follow national trends, adjusted by state-specific change in fertility rates ( ) Mortality:  Follow national trends, adjusted by state-specific change in mortality rates ( ) Internal migration:  Follow the IRS migration trends in region-to-state and state-to-region migration flows.  Hold the composition of census migration flows constant. International migration:  Follow current international migration trends in the states and determined by projected net international migration for the U.S.  Hold constant the composition of immigrant population in the state

20 Fertility Rate Projection Population base  Female base year population  Female expected survived population Project fertility rates  Starting age-specific fertility rates… (f(t-1))  Projected national total fertility rates… (F(t))  Ratio of state total fertility rate change to national total fertility change… [f(2000)/f(1990)]/[F(2000 /F(1990)] Projection formula:  f(t) = f(t-1) + (F(t) - F(t-1)) * [(f(2000)/f(1990)) / (F(2000)/F(1990))]

21 Survival Rate Projection Project survival rates  Starting age-specific survival rates… (s(t-1))  Projected national survival rates… (Sn(t))  Adjustment factor – Ratio of state-specific survival rate change to national survival rate change, using one minus probability of dying (1-Qx) by 5-year age… [s(2000)/s(1990)] / [Sn(2000)/Sn(1990)] Projection formula:  s(t) = s(t-1) + (Sn(t) – Sn(t-1)) * [(s(2000)/s(1990)) / (Sn(2000)/Sn(1990))]

22 Projection of IRS Migration Flows Input time series (28 data points):  204 region-to-state migration rates ( to )  204 state-to-region migration rates ( to ) ARIMA time series projections of first difference in natural log of migration rates for the first 5 years (Using SAS program) Interpolation from 5 th year projected migration rates toward mean in the next 20 years Hold the mean constant for remaining projection years

23 International Migration Projection Project total net international migration by state based on the estimates of net international migration, Project composition of net international migration  Population base  Proportion of foreign-born population  Control to projected total net international migration Control to projected national international migration for the U.S.

24 Proposed Products Detailed age, sex, race, and Hispanic origin for all states, year by year ( ) Detailed age, sex, race, and Hispanic origin with components annually for individual states Summary tables with statistics such as median age, dependency ratio, sex ratio, etc. and graphs such as population pyramids.

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