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

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DRAFT COUNTY PROFILE (DATA) ELEMENT APPENDIX .............. .. ... ...... group which was male (or female) was assumed to be the average of the corresponding fractions for the calendar years 1995 through 2004. DEATH ASSUNIPTIONS.... As in the previous set of estimates, unabridged life tables for 1990 from the National Center for Health Statistics were available for these estimates. North Carolina's death rates based on these tables were fairly close to those of the nation as a whole, with rates for some age groups within each race/sex group higher for the state and rates for some groups lower. Over the next several decades, North Carolina's death rates are expected to converge toward national rates, reaching fall equality by the year 2050. This assumption was used to develop projected survival rates for North Carolina for 2000, 2010, 2010, and 2030 from 1990 North Carolina survival rates and projected United States survival rates (Population Projections Branch, Population Division, U. S. Bureau of the Census). Since the North Carolina nonwhite population is overwhelmingly black (91.6 % in 1990) and the national nonwhite population is much less so (76.2 %), North Carolina nonwhite rates were converged to national black rates. In calculating the deaths for each race-sex group for the 1990s, the survival rates for 2000 were adjusted to yield the actual number of state deaths, assuming that the average survival rate for the decade was the simple geometric average of the rate for 1990 and the adjusted rate for 2000. Then, the adjusted rates were converged toward national rates. For the 2000s, the 2010s and the 2020s, the average survival rate for the decade was assumed to be the simple geometric average of the rate at the beginning of the decade and the corresponding rate at the end of the decade. METHODOLOGY.... BASIC TREND PROJECTIONS BY COUNTY The basic technique used to develop county trend projections by age, race, and sex for this series is the Adjusted Migration technique. The first step in this procedure is to obtain survived net migration for the base decade. First, county/state survival rate factors for each county for each race are developed using actual county deaths by race for the 1990-2000 decade. These factors are assumed to be reasonably valid throughout the projection period. Then, one obtains a "Cohort Survived" population (assumes no net migration during the base decade) for the end of the base decade by applying these factors and state survival rates to the population at the beginning of the base decade. Finally, one subtracts this "Cohort Survived" population from the population at the end of the base decade to get the desired survived net migration.- The next step is to adjust this survived net migration for the base decade to yield a survived net migration for the projection decade. The adjustment procedure has two branches. If the survived net migration for a given age, race, and sex group is in-migration, then it is adjusted only for differences in mortality between decades. If it is out-migration, then it is adjusted both for mortality differences and for the change in population between the beginning and end of the base decade. There are two final steps. First, a "Cohort Survived" population is calculated for the projection date in a manner similar to that used to calculate the "Cohort Survived" population for the end of the base decade. Then, the survived net migration for the projection decade is added to this "Cohort Survived" population to yield the final projected population. 8/16/2007