06-24-1985 Council Packet - Laserfiche WebLink

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APPENDIX REGIONAL POPULATION AND HOUSEHOLD FORECASTS The regional population forecast Was prepared using the cohort survival model. It is a widely used, relatively simple way of applying assumptions to project future population change for different age groups. The 1980 Census population and age distribution by sex provided the basis of these regional forecasts. Each cohort (group of people the same age) is advanced or aged one year at a time until the desired forecast year is reached. The number of people still in the age group each year is equal to the number that survived, minus the number that moved out of the region, plus the number that moved in. Each year's births are calculated by multiplying the number of women in each age group by the percentage likely to have a child that year. The forecast uses assumptions about the number of people that will survive, the fertility rate and migration. Future survival rates were assumed to stay the same as in 1980, except for the future elderly; they are projected to live longer. Recent evidence shows less people are dying from heart disease. The fertility rates were held at the 1980 level. A few mcre people moved out of the region than into it during the last decade --a reversal of the trend of the previous two decades. The migration assumptions resulted in a slight future net migration loss. It was assumed that both in- and out -migration would drop slightly over the period from 1980 to 2000. Less people are expected to be in the age ranges that have the highest mobility. Households were forecasted using assumptions regarding the rate at which people of different ayes form households. It was assumed that these rates would remain the sar• 5y age) as they were in 1980. To determine the number of households for a future year, the household formation rates were multiplied by the forecasted population by age. The household forecasts reflect the historically high household formation rates of 1980, but do not further increase the rates for 1990 and 2000. In light of the sharp drop in household formation rates during the recent recession, this seems appropriate. The employment forecasts are consistent with the labor force expected in 1990 and 2000, even though employment was not derived from the demographic forecasts. REGIONAL EMPLOYME'IT FORECASTS Employment for 1990 and 2000 was calculated from regression equations. The equations were derived from analysis of a special series of total nonagri- cultural employment for the seven -county area and United States total nonagri- cultural employment from 1958 to 1983. Two equations were used for each category, such as manufacturing, services and retail. One equation made local employment a function of national employment. To obtain 1990 figures, a Bureau of Labor Statistics forecast of national employment was simply substituted into the equation. The other equation was a trend line. The 2000 forecasts are a continuation of the trend from 1958 to 1983. MCD HOUSEHOLD FORECASTS The primary data for the MCD household forecasts were the 1970 and 1980 Censuses, annu-1 residential building permits and the amount of developable land left in a city. (A household is an occupied housing unit either a 18