Scientific Data Documentation

Intercensal Population Estimates, NCHS 1981-1989

y8189.nchs.zip


 Annoucement: January/February 1993
 Abstract
 Methodology
 Record Layout




 ANNOUNCEMENT:  INTERCENSAL USAGE NOTES/NEWS


 Source:  APDU Newsletter
          Volume 17, No. 1
          January/February 1993


 Director Announces No Adjustment ofIntercensal Estimates

 Barbara Bryant, Director of the Bureau of the Census, announced on
 December 29 that the intercensal population estimates produced annually
 by the Bureau will not be adjusted to correct for the estimated 1.6%
 national net undercount in the 1990 census. This was one of the last acts of
 Bryant, who left her position on January 20,1993. Harry Scarr, Deputy
 Director, is now the senior official at the Census Bureau.

 "This decision was difficult to make," Bryant said in her notice to the
 Federal Renter. "It is the consensus of a committee of senior Census Bureau
 statisticians and demographers that adjustment would improve the accuracy of
 the 1990 census count at the national level, particularly for racial/ethnic
 and owner/renter groups. Adjustment would also more accurately depict most
 states' shares of the national population. The accuracy of the 1990 census
 is important to the intercensal adjustment issue because the 1990 figure is
 the startmg point for our yearly population estimates. However, because  the
 1990 total undercount is so small (less than 2 percent), it is impossible to
 accurately adjust for the 44,055 substate areas for which population
 estimates are produced."

 Bryant noted that sponsors of federal surveys conducted by the Census
 Bureau will be offered the option of calibrating their surveys to adjusted or
 unadjusted population estimates beginnmg in 1993. These would be such surveys
 as the Current Population Survey, the National Health Interview Survey, and
 the National Crime Victimization Survey. These national surveys are
 calibrated at large, aggregate levels where Census Bureau research shows
 adjusted estimates are on average more accurate.

 Bryant also pointed out that unadjusted estimates remain the official
 population totals. Federal law requires that the Census Bureau issue official
 totals for use in any federal program which allocates its funding based upon
 population estimates.  The Census Bureau provides official population
 estimates to states and counties in every year between decenrialcensuses and
 to subcounty areas every other year. Estimates of US population as of July 1,
 1992, were released on January 1,1993.

 * Reprinted with permission of the Association of Public Data Users (APDU)
   For membership information contact:

                             Susan Anderson
                             (609) 258-6025 or
                             (609) 258-6052


 ABSTRACT

 These data are estimates of the population of the 3,136 counties in the United
 States as defined in 1980, by 5-year age groups (age 0 to 4, 5 to 9, ...85
 and over), sex (male, female), and modified race (White, Black, other races)
 for each year, July 1, 1981 through July 1, 1989.  The estimates included in
 this release are developed by interpolating between census files for April 1,
 1980 and 1990.  The interpolations were adjusted to be consistent with pre-
 liminary intercensal estimates of the total population of the United States,
 states, and counties.

 The age and race data in the 1980 and 1990 Census data files which were used
 as anchor points in this methodology were modified to be consistent with
 other data sets.




 METHODOLOGY

 This section describes briefly the methodology used to derive the attached
 preliminary intercensal estimates of the resident population of States,
 divisions, and regions for July 1, 1981 to 1989.

 The intercensals are consistent with the 1980 census counts as published in
 the U.S. Census Summary, PC80-1-B1 and the 1990 census count was enumerated.
 The latest set of 1981-90 (1980-based) State estimates were used in the
 intercensal formula (1).  The sum of the intercensal state estimates for each
 year was adjusted to be consistent with independent national estimates of the
 intercensal population estimates.

 This procedure was also used in developing the annual intercensal population
 estimates for the United States (2).

 The user should note the intercensal estimates presented are preliminary for
 the following reasons.  First, the April 1, 1990, State and National post-
 censal estimates used to compute the intercensal estimates use provisional
 input data that will be revised.

 Secondly, both the State and National postcensal estimates use methodologies
 that are subject to change once an evaluation of the postcensal population
 estimates is completed.  At least one other series of annual State and
 intercensal estimates of the population is planned for release in the next
 two years.

 (1) The methodology for 1980-based estimates is described in Current
     Population Reports, Series P-25 Nos. 957 and 998.

 (2) The final report from the Bureau of the Census's Intercensal Working
     Group may be obtained by calling (301) 763-5072.


 RECORD LAYOUT

 Six Records (by Race/Sex) per county, 3136 counties (1980 Geography)
 Year = July 1, 1981, ... July 1, 1989

 Record      Contents                               Columns

 Year        (2 digits, 81, ...89)                  1-2
 FIPS        (State/County)                         3-7
 Race/Sex    (1=white male, 2=white female,
              3=black male, 4=black female,
              5=other male, 6=other female)         8
 Blank                                              9
 Age         0-4                                    10-17
             5-9                                    18-25
             10-14                                  26-33
             15-19                                  34-41
             20-24                                  42-49
             25-29                                  50-57
             30-34                                  58-65
             35-39                                  66-73
             40-44                                  74-81
             45-49                                  82-89
             50-54                                  90-97
             55-59                                  98-105
             60-64                                  106-113
             65-69                                  114-121
             70-74                                  122-129
             75-79                                  130-137
             80-84                                  138-145
             85+                                    146-153