# Presentation: 281274

## National Projections Program, 2005Population Projections BranchPopulation DivisionU.S. Census Bureau

## Two series under consideration

- Interim projections, released in spring of 2004
- Population forecasts under development, future release

## Interim projections, production overview

- Initially produced by International Program Center (IPC) for International Database (IDB), resident plus Armed Forces overseas by age and sex, 2000 through 2050.
- Race and Hispanic origin detail added, early 2003, reduced to resident population
- Resident population by age, sex, race, and Hispanic origin released, spring of 2004

## Interim projections, technical attributes in brief

- Incorporated Census 2000 as base
- Adapted component assumptions from existing projections, released early 2000.
- Corrected to population estimates component assumptions for 2001, by mixing high, medium, and low series
- Major change in imputation of race of child, based on OMB 1997 guidelines: “check all that apply”

## Interim component assumptions

- Components not race-specific:  race and ethnic composition effects from old series present, but not updated
- Very slight decrease in fertility from old middle series—still a rise above TFR=2.2, then a slight decline
- No change in mortality from old middle: e0=81.2 for males, e0=86.7 for females (2050)
- Slight increase in international migration from old middle series, but no revision of decline in early 2000s

## Race of child:  the problem

- OMB guidelines yield 62 categories of 5 major race and 2 Hispanic origin responses:  (25-1)*2
- Interim projections have only 8 cross-categories of race and origin
- Race of child not generally same as race of parent:  race/origin groups not “closed” with respect to reproduction

## Race of child:  assumptions

- Transmission of race and Hispanic origin from parent to child follows census universe, not biological “rules”
- We can approximate transmission from structure of households
- Mixed-race childbearing stays at baseline levels, except for demographic supply effects

## Race of child:  census input

- Census 2000 (100%) tabulation of households with parents and non-adoptive children under 18 by race and Hispanic origin
- Imputed race of missing fathers by race of mother and race of children
- Race of child may not “agree” with either Mom or Dad:  OK

## Race of child:  imputation

- Apply fertility rates to projected women to yield new mothers by race and origin
- Tabulate potential fathers by race and origin, and age of mother
- Measure shift in distribution of potential fathers from base date to target date via multiple logits
- Impose multiple-logit shift on actual distribution of fathers in census household file, to yield joint distribution of mothers, fathers by race and Hispanic origin
- Impute race of child from joint distribution, based on census household file

## Forecasts under development

- Greater emphasis on historical time series in formulating assumptions
- More systematic approaches to derivation of future trends in components
- Measurement of uncertainty:  prediction intervals
- “Min-max” race, but technical innovations directed to three large groups that are close to old definition
- Any innovation in method is likely to appear as an “experimental” product