# Presentation: 339247

## STATE AND COUNTY CHARACTERISTICS ESTIMATES

- A DETAILED DESCRIPTION OF THE VINTAGE 2003 METHODS AND PROCESSING

## Workshop Overview

- Introduction
- History and general concepts
- State age-sex method and processing
- State and county characteristics method and processing
- Summary and discussion

## History and General Concepts:  Historical Overview

- 1970s
- Started producing state estimates by selected age groups in the 1970s; added sex later in the ’70s
- 1980s
- Started producing state estimates by single years of age and sex using the current method
- Early 1990s
- Released first set of state estimates by age, sex, race, and Hispanic origin produced by the current method
- 2000s
- Released first set of county estimates by age, sex, race, and Hispanic origin produced by the current method

## History and General Concepts:  General Concepts

- Universes
- Resident
- Civilian vs. Military
- Household vs. GQ
- Institutional vs. Noninstitutional
- Migration
- International, Domestic, and Total
- Ins, Outs, and Net
- Interstate and Intrastate

## History and General Concepts:  General Concepts (cont.)

- Proportional Distribution Technique
- Purpose is to achieve consistency among estimates
- Basic method
- Develop initial version of new estimates
- Create proportions from new estimates that correspond to the estimates you want to distribute
- Multiply the proportions by the previously developed estimates
- Distributing two sets of estimates
- This procedure is done first to one set then to another
- Typically, it is necessary to repeat the back-and-forth procedure several times

## History and General Concepts:  General Concepts (cont.)

- Example – State Age-Sex
- Create and initial set of state estimates by age and sex
- Create proportions of the national estimates by age and sex and proportions of the state totals
- Multiply the proportions by the previously developed estimates

## History and General Concepts:  General Concepts (cont.)

- Approaches to creating time series
- _Whole interval approach_: the beginning population for the estimate of each year in the time series is Census 2000
- _Year-to-year approach_: the beginning population for the estimates of each year in the time series is the estimates for the previous year of the time series

## State Age-Sex:  Overview

- The basics
- The general method
- Beginning populations
- Deaths
- Migration
- 65+ population estimates

## State Age-Sex:  The Basics

- State population
- Single years of age (0 – 84) and 85+ by sex
- Whole interval approach

## State Age-Sex:  The General Method

- Calculate proportions
- Create the civilian beginning populations and add births*
- Subtract deaths*
- Calculate estimated net migration and add*
- Apply sex proportions to get population by sex
- Add military to get resident population
- Create proportions
- Use proportions to distribute previous  estimates
- National estimates by age and sex
- State totals estimates

- * will be discussed in detail in this workshop

## State Age-Sex:  Base Population

- Start with GUSSIE resident base population
- By single years of age and sex
- Age the population forward to age in estimate year
- Add male and female population together
- Add birth data to the youngest ages
- Subtract out the military population to get the final civilian beginning population

## State Age-Sex:  Deaths

- Begin with deaths to the resident population by single years of age (0-84, 85+) and sex
- Collapse into both-sexes deaths by age
- Sum deaths to estimate intervals (Census date to Estimate date)
- Subtract military deaths to obtain preliminary civilian deaths by age
- Control to national civilian deaths by age from National Estimates to arrive at final civilian deaths by age

## State Age-Sex:  Migration, Ages 0 - 16

- Develop an estimate of the total school age population (ages 6 to 14) for each estimate year
- Distribute the national estimates for ages 6-14 to the states using proportions developed from school enrollment data
- Develop a set of state school age population estimates under the assumption of no migration
- Survive the cohorts that become the school age population in the estimates year from Census 2000 to each estimate year using deaths from vital registration
- Migration = [#1] – [#2]
- Distribute to single years of age 0 to 16

## State Age-Sex:  School-Age Migration Rates

- Begin with the estimates of migration of the school age population from the previous step
- Create an estimate of the mid-interval school-age population (6 to 14) for each estimate interval
- Subtract 1⁄2 of the estimate of the cumulative school-age deaths for each estimate interval from the Census 2000 school-age population
- Create the school age migration rates
- Divide the estimates of school-age migration for each estimate interval by the corresponding mid-interval estimate of the school age population

## State Age-Sex:  Migration Differentials

- Begin with census data from 5-year residence question (ignoring sampling variability)
- Calculate in and out migration rates by state and single year of age (0-84) and 85+ and smooth by age
- Combine in and out rates into a net migration rate
- Multiply net rates by a series of mid-interval populations over a 10-year interval to arrive at 10 annual estimates of migration per cohort

## State Age-Sex:  Migration Differentials (cont.)

- Sum migrants by cohort and collapse summed migrants ages 6-14 into one group
- Create new migration rates by dividing summed migrants ages 6-14 as a group and 17-64 migrants by SYA by the corresponding population at the beginning of the interval
- Subtract school age migration rate from each SYA migration rate to get migration differentials.

## State Age-Sex:  Migration, Ages 17 - 64

- Begin with school age migration rates
- Migration rates by single year of age 17 to 64 = school age migration rate + single year of age migration differentials
- Migration = Single-year rates * estimates of mid-interval population
- Mid-interval population = Base population + 1⁄2 interval deaths

## State Age-Sex:  Population Estimates, 65+

- Start with Medicare data by state, sex and 5-year age groups 65-84 and 85+
- Extrapolate values for 4/1/00 and missing estimate years
- Control to Medicare totals used in state-county totals estimates
- Distribute by single years of age using cohort distributions from Census 2000
- Calculate implied population change since 4/1/00  (estimated population – beginning population) and add to beginning population
- Control estimates to National Estimates

## State Age-Sex:  Summary

- Calculate proportions
- Create the civilian beginning populations and add births
- Subtract deaths
- Calculate estimated net migration and add
- Apply sex proportions to get population by sex
- Add military to get resident population
- Create proportions
- Use proportions to distribute previous  estimates
- National estimates by age and sex
- State totals estimates

## State & County Characteristics:  Overview

- The basics
- The general method
- July 1, 2000 beginning population
- Race conversion (31 to 4)
- Domestic migration
- IRS pre-processing
- State domestic migration
- County domestic migration
- Race conversion (4 to 31)

## State & County Characteristics:  The Basics

- State and county population
- Single years of age (0 – 84) and 85+ by sex, race (31 races), and Hispanic origin
- Year-to-year approach

## State & County Characteristics:  The General Method

- Calculate proportions
- Produce July 1, 2000 beginning population*
- Add births, subtract deaths, add net international migration, and add military movement
- Add domestic in-migration and subtract domestic out-migration*
- Create proportions
- Use proportions to distribute previous estimates*
- State: National characteristics and state age-sex
- County: State characteristics and county totals
- Convert from 4 to 31 races*

- * will be discussed in detail in this workshop

## State & County Characteristics:  July 1, 2000 Beginning Population

- Calculate proportions
- Begin with GUSSIE base
- Convert from 31 to 4 races*
- Remove GQ population to get household population
- Create proportions
- Use proportions to distribute previous July 1, 2000 household estimates*
- State: National characteristics and state age-sex
- County: State characteristics and county totals
- Add GQ population to get final resident beginning population

- * will be discussed in detail in this workshop

## State & County Characteristics:  July 1, 2000 Beginning Population  (cont.)

- Race conversion: 31 to 4
- Equi-proportional assignment of persons in multi-race categories to single-race categories (31 to 5 categories)
- Combine Asian and NHOPI categories into API (5 to 4 categories)

## State & County Characteristics:  Domestic Migration

- Pre-process IRS migration data
- State domestic migration
- Create state out-migration rates and out-migrants
- Create state in-migration proportions and in-migrants
- County domestic migration
- Create intrastate migration rates and migrants
- Distribute interstate migration flows to counties
- Distribute intrastate migration to counties

## State & County Characteristics:  Domestic Migration – IRS Pre-  Processing

- Obtain administrative record data
- Define the migration universe
- Determine the number of exemptions
- Assign characteristics
- Define migration status

## State & County Characteristics:  Obtain Administrative Record Data

- Migration status
- Internal Revenue Service (IRS) 1040
- SSN of filer
- Address of filer
- Number of exemptions claimed on return
- Demographic characteristics
- Census Numident Person Characteristics File (PCF)
- Modeled age, sex, race, and Hispanic origin of filer
- Derived from Social Security Administration Numident File

## State & County Characteristics:  Define the Migration Universe

- Start with tax return files from April 15, 2002 (Y1) and April 15, 2003 (Y2)
- Convert SSN on tax records to Protected Identifier Key (PIK)
- Match Y1 and Y2 files by filer’s PIK
- Define the universe
- Includes Y1-Y2 matches
- Excludes non-matches, foreign addresses, and 1040NR records

## State & County Characteristics:  Determine the Number of  Exemptions

- Convert matched file from a return-based file to a person-based file
- Produce an individual record for each exemption claimed on each return
- Identify spouse, child(ren), and parent(s) records

## State & County Characteristics:  Assign Characteristics

- Age
- Filer and spouse are assigned filer’s age from the PCF
- Child is assumed to be under 20 years
- Parent is assumed to be 65 or over
- Sex
- Filer is assigned filer’s sex from PCF
- Spouse is assigned opposite sex of filer
- Child and Parent are assigned sex by random number generator

## State & County Characteristics:  Assign Characteristics (cont.)

- Race and Hispanic origin
- Filer, spouse, child, and parent are all assigned filer’s race and Hispanic origin from PCF
- Because number of non-White Hispanics is small, all races are combined for Hispanics

## State & County Characteristics:  Tallying Exemptions

- Tallies of exemptions are used to calculate three different measures:
- Inter-state migration rates
- Intra-state migration rates
- County migration shares
- Inter-state migration rates require tallies of state of residence at beginning of interval by state of residence at end of interval by age, sex, race, and Hispanic origin (ASRH)
- Intra-state migration rates require tallies for each state of those exemptions where state of residence is the same at beginning and end of interval but county of residence is changed, by ASRH

## State & County Characteristics:  Tallying Exemptions (cont.)

- Four different types of county migration shares are computed, each requires race and Hispanic origin detail:
- Inter-state out-shares use tallies for each state and county at the beginning of the period by all other states at the end of the period
- Intra-state out-shares use tallies for each state and county at the beginning of the period by all other counties in that state at the end of the period
- Inter-state in-shares use tallies for each state and county at the end of the period by all other states at the beginning of the period
- Intra-state in-shares use tallies for each state and county at the end of the period by all other counties in that state at the beginning of the period

## State & County Characteristics:  State Domestic Migration

- Calculations are performed by single year of age, race, sex and Hispanic origin where possible
- Exceptions:
- For Hispanics, all races are combined into one category
- Ages 0 to 19 are combined into one category

## State & County Characteristics:  State Domestic Migration (cont.)

- Exceptions (cont):
- Ages 65 and over are combined into one category
- If there are less than 30 exemptions for an ASRH combination, additional ages are included until the threshold of 30 exemptions is met
- Each ASRH combination within a category is assigned the rate or proportion calculated for the category

## State & County Characteristics:  State Domestic Migration (cont.)

- Calculate a set of state out migration rates
- Out migration rate = # of exemptions leaving the state / # of exemptions in the state
- Smooth the out migration rates by age
- Calculate a set of state to state migration rates
- State to state migration rate = # of exemptions moving from state X to state Y / total # of exemptions in state X

## State & County Characteristics:  State Domestic Migration (cont.)

- Calculate a set of preliminary estimates of in migration by state
- Preliminary state in migrants for state X = ∑(state to state migration rate from state Y to state X * Vintage 2002 state population state Y)
- Sum all states’ in migrant estimates to get total in migration

## State & County Characteristics:  State Domestic Migration (cont.)

- Calculate each state’s in migration proportion
- State in migration proportion = preliminary state in migrants / total in migration
- Smooth the in migration proportions by age

## State & County Characteristics:  State Domestic Migration (cont.)

- Final estimates of out and in migrants by state are calculated in the process of estimating household population
- State out migrants = state out migration rate * state population at the beginning of the time interval
- State in migrants = state in proportion *  ∑(state out migrants)

## State & County Characteristics:  State-level Summary

- Calculate proportions
- Produce beginning population
- Add births, subtract deaths, add net international migration, and add military movement
- Add domestic in-migration and subtract domestic out-migration
- Create proportions
- Use proportions to distribute national characteristics and state age-sex estimates
- Convert from 4 to 31 races

## State & County Characteristics:  County Interstate Domestic Migration

- State domestic migration is distributed to the county-level
- Two types of ratios are computed
- migration rate = # of migrating exemptions  / # of exemptions
- migration share = # of migrating exemptions in the county / # of migrating exemptions in the state

## State & County Characteristics:  County Interstate Domestic Migration  (cont.)

- Migration rates are used to compute state-level migration with full detail
- Three types of state-level migration are computed: in-migration, out-migration, and within-state migration
- County migration shares are used to divide state-level migration among counties by race and ethnicity
- All counties are assumed to have the same migration patterns by age and sex as the state

## State & County Characteristics:  County Intrastate Domestic Migration

- County intrastate migration share = # of intrastate migrating exemptions in the county / # of intrastate migrating exemptions in the state

## State & County Characteristics:  Race Conversion (4 to 31)

- Calculate conversion factors for 31 to 4 race conversion from the Census 2000 GUSSIE population
- Apply conversion factors to population in each 4-race category to get population in each 31-race category

## State & County Characteristics:  Summary

- Calculate proportions
- Produce beginning population
- Add births, subtract deaths, add net international migration, and add military movement
- Add domestic in-migration and subtract domestic out-migration
- Create proportions
- Use proportions to distribute previous estimates
- State: National characteristics and state age-sex
- County: State characteristics and county totals
- Convert from 4 to 31 races

## Characteristics Estimates:  Comparison of the Methods

- Processing universes
- Controls
- Processing components
- Base population
- Estimated births
- Estimated deaths
- Estimated migration
- Use of Medicare data

## Issues for the Future:  General

- Which universe(s) should we process in?
- What is the best method for using rates in the estimates?
- What are the appropriate geographic and characteristics levels for projecting components of change?
- What is the best way to calculate domestic migration?

## Issues for the Future:  General (cont.)

- What is the best way to perform proportional distribution and controlled rounding?
- How should we estimate populations for which we have registries (school age population, 65+ population)?

## Issues for the Future:  General (cont.)

- How can we maximize the resources of FSCPE members?
- Information on components of population change?
- Symptomatic indicators of population or component change?
- State-produced population estimates?
- Input from review?

## Issues for the Future:  State Age-Sex

- Should we continue to process using the whole-interval approach?
- Should we process by sex as well as age?

## Issues for the Future:  State & County Characteristics

- Can we move from 1990 race based processing to 2000 race based processing?
- Will person-based IRS migration give us better estimates of domestic movement than return-based migration?

## Issues for the Future:  State & County Characteristics  (cont.)

- Should we calculate intrastate migrants at the county level instead of calculating them at the state level and distributing to counties?
- Should we continue to use the previous vintage of estimates in intermediate processing?