(please type or print) OUR but of interest to EVERYONE! U.S. DEPARTMENT OF COMMERCE Social and Economic Statistics Administration BUREAU OF THE CENSUS 36.218: P-26 DEPARTMENT UNITED OF COMMERCE STATES OF AMERICA DOES NOT CIRCULATE CURRENT POPULATION REPORTS FEDERAL-STATE COOPERATIVE PROGRAM FOR Population Estimates U. S. DEPARTMENT OF COMMERCE Social and Economic Statistics Administration BUREAU OF THE CENSUS This report presents population estimates for July 1, 1972 and provisional estimates for July 1, 1973, for counties and metropolitan areas prepared under the auspices of the FederalState Cooperative Program for Local Population Estimates. The objective of this program is the development and publication of State-prepared estimates of the population of counties using uniform procedures largely standardized for data input and methodology. The methods used have been mutually agreed upon by the individual States and the Bureau of the Census on the basis of a test of methods against the 1970 census. For a more detailed description of the program and an analysis of the test results, see Current Population Reports, Series P-26, No. 21, "Federal-State Cooperative Program for Local Population Estimates: Test Results-April 1, 1970, April 1973. County estimates for July 1, 1971 and provisional estimates for July 1, 1972 were published earlier in Current Population Reports, Series P-26, No. 31. The provisional estimates in that report are superseded by the numbers published here. Because of changes in input data for some counties since that report, estimates shown here may not always be completely comparable with those for the earlier years. The estimates shown here for the 99 counties in the State were prepared by the Records and Statistics Division of the Iowa State Department of Health in cooperation with the Bureau of the Census. This agency was designated by the Governor to work with the Bureau of the Census in implementing and carrying out the FederalState Cooperative Program. The estimates shown for July 1, 1972 are based on an average of the following methods, adjusted to agree with the July 1, 1972 State estimates published in Series P-25, No. 508. 1. The Regression (ratio-correlation) method. In the Regression method a multiple regression equation is used to relate changes in a number of different data series to change in population distribution.1 The series of data used in the Regression method for Iowa are: automobile registrations (X), two-year averages of resident births (X2), two-year averages of resident deaths (X3), and elementary school enrollment in grades 1 through 8 plus elementary special and elementary ungraded (X). The prediction equation for Iowa for the 1970's is given by For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402, and U.S. Department of Commerce district offices. Price 25 cents. Current Population Reports issued in Series P-20, P-23, P-25, P-26, P-27, P-28 (summaries only), P-60, and P-65 are sold as a single consolidated subscription at $30.50 per year, $7.75 additional for foreign mailing. 2. Component Method II, This method employs vital statistics to measure natural increase and school enrollment to measure net migration. The estimates made by the Census Bureau's Component Method II are specific to the civilian population under 65. To this population is added. an estimate of the resident military population based on station strength statistics and an estimate of the population 65 and over based on Medicare statistics.1 3. The Composite method. In this method estimates of various age groups are derived separately and are then summed to secure a total for all ages. Death statistics are used to estimate the population in ages 45 and over, birth statistics are used to estimate the population in ages 18 to 44, and a variation of Component Method II is used to estimate the population in ages under 18. In the case of birth and death statistics, an arithmetic average of two years of data is used for both the base year (1970) and the estimate year (1972). The two-year average is used to smooth out random fluctuations in the data which distort the estimates.1 The provisional July 1, 1973 estimates for large metropolitan counties were developed by adding the average change between 1972 and 1973 estimates based on Component Method II and the Housing Unit method to the 1972 estimates. In the Housing Unit method the estimates of population are based on estimates of the housing inventory. Changes in the housing inventory are derived from data on building permits issued and demolition records, or on data on electric meter connections. The provisional July 1, 1973 See footnote 1 on page 1. estimates for the remaining counties were developed by adding the change between 1972 and 1973 Component Method II estimates to the 1972 estimates. All counties were subsequently adjusted to agree with the provisional July 1, 1973 State estimate published in Current Population Reports, Series P-25, No. 508. Table 2 of this report presents estimates of the population of metropolitan areas and metropolitan counties in the State. The titles and definitions of the standard metropolitan statistical areas (SMSA's) are those currently defined by the Office of Management and Budget, Executive Office of the President. Where an SMSA falls in more than one State (indicated in the SMSA title) information on the other State parts of the area can be obtained by referring to the P-26 report for the other States. Corresponding estimates for other States in the program will be published as they become available. The appendix table shows reports published to date for States in the 1972-73 series, together with those published earlier for 1971 and provisional 1972. The 1970 census total for the State shown on the table may differ slightly from the sum of the counties because of corrections made subsequent to the release of the official State figure. All county populations for 1970 reflect corrections in the census count published in the bound 1970 census volume for the State. The estimates presented in the table have been rounded to the nearest hundred without being adjusted to the State total, which was independently rounded to the nearest thousand. Percentages are based on unrounded numbers. |