Agenda - 09-19-2007-6f1 - Laserfiche WebLink

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DRAFT COUNTY PROFILE (DATA) ELEMENT APPENDIX BASIC DATA.... The most fundamental basis for these projections are population values for North Carolina and its counties from the Census Bureau's 2000 Census of Population. Since the last projection series, there have been a few minor corrections based on Census Bureau boundary changes. These projections use single year of age totals (0 -94) and one composite age group (95 +) by male and female from the 2000 Census for the data for the 2nd year of the base decade. An estimate of the "White" fraction of each age group for each gender was made to create the detailed population for April 2000. An estimate of "White" is necessary because the 2000 Census data does not define races in the same way as the 1990 Census data does. It does not define a single racial value for "White ". The-goal-oft he estimation procedure was to create a _ "White'T'Other" split which would match that of the 1990 Census. The "White" and "Other" values used for projected years are based on these estimates for April 2000 and corresponding values from the 1990 Census. For more details about the estimation procedure, click here. The "aging forward" of this 2000 population base strongly affects these age, race, and sex specific projections. This effect causes projected births to rise more slowly than projected population, in spite of fertility rates which are assumed to remain constant. It causes projected deaths to increase more rapidly, in spite of improving mortality. Population values for North Carolina and its counties from the Census Bureau's 1990 Census of Population are very important as well. The actual data came from the Census Bureau's MARS (Modified Age, Race, and Sex) file. The original 1990 Census files included errors nationwide in the. age tabulations which made as many as 20 percent of the population in a given age group one year older on April 1, 1990 than they really were. The age error correction technique used in the preparation of the MARS file incorporated national birth data by quarter of the year from 1920 through 1990. For the MARS file, the unclassified "other" race group in the original 1990 Census data was distributed to the four basic race groups ( "white ", "black ", "Indian ", and "Asian "). The most critical use of these values is in the determination of detailed migration trends for the 1990 -2000 time period. The values in the 1990 population base include adjustments to the original MARS file values based on postcensus corrections received from the Census Bureau. BIRTH ASSUMPTIONS.... Since the early 1990s, North Carolina's fertility rates have changed significantly. North Carolina fertility rates for white mothers leveled out during the first half of the 1990s, increased rapidly during the second half of the 1990s, and are currently leveling out or increasing slightly. The fertility rate for nonwhite mothers dropped in the first half of the 1990s, rose somewhat in the second half of the 1990s, and has recently dropped again. Currently (2002, 2003, and 2004), it is below that of white mothers for the first time in decades. It was assumed that fertility rates for all age and race groups would be constant from 2005 through 2030. To obtain a more stable set of future rates, the fertility rates for 2002 -2003, the fertility rates for 2003 -2004, and the fertility rates for 2004 -2005 were averaged. The distribution of births into male and female for each race group was also assumed to be constant from 2005 through the year 2030. The fraction of the projected births for each age 8 8/16/2007