This report provides revised population and housing estimates for the state, counties and cities for January 1, 2000. Separate totals for incorporated and unincorporated areas of counties are included.

Methodology

Introduction. The estimates’ benchmark is the April 1, 1990 U.S. Census of Population and Housing. City and unincorporated area population estimates are calculated and summed for each county and adjusted to independently estimated county controls. The county estimates are controlled to the independently estimated state population. The controlling process is used because the estimating models that produce more accurate population estimates require data that are only available at the county and state levels.

City and Unincorporated Area Estimates. The Housing Unit (HU) Method estimates total and occupied housing units, household size and population, and group quarters population. HUs are estimated by adding new construction and annexations and subtracting demolitions from the census benchmark. HU changes have been supplied by the U.S Census Bureau and various local jurisdictions. Occupied HUs are estimated by applying a Demographic Research Unit (DRU) derived civilian vacancy rate based on 1990 census data, to estimated civilian HUs plus the occupied military units. Military surveys are used to track military changes, including base realignments and closures. The household population is derived by multiplying the current persons per household estimate by the occupied HUs. The census group quarters population is updated using the reported population change in group quarters facilities. Household and group quarters populations are summed to produce the total population estimates.

County Estimates. The county population estimates result from applying the average proportionate distribution resulting from three independent methods for estimating county proportions of the independent state estimate.

The Household Method estimates the annual proportionate change in each county’s distribution of households compared to the prior year. The estimated change is applied to the prior estimated distribution of the household population. Group quarters estimates are then added.

The Ratio Correlation Method models change in household population as a function of changes in the distributions of driver licenses, enrollments, and labor force. Estimates of county group quarters are added.

The DLAC Method is a version of the Driver License Address Change method modified for counties. Shifts in the county-level allocation of estimated proportions result from relative annual change in county population values as a function of births, deaths, and foreign and domestic migration.

State Estimate. The state population is estimated using the Driver License Address Change (DLAC) Method. This composite method takes account of annual births and deaths and features distinctive approaches to groups under age 18, aged 18 thru 64, and 65 and over. Driver license address changes, tax return data, Medicare enrollment, and immigration data are among the data used in this method, which includes survived cohorts of household population, group-specific migration estimates, and group quarters population.

Data Considerations

Sources. Data used in estimation models come from administrative records of seventeen State and federal departments and agencies, as well as numerous local jurisdictions. Since timeliness and coverage in these series vary, corrections, smoothing and other adjustments may be applied.

Accuracy. Data and models used to produce estimates are subject to measurement and nonmeasurement error, resulting in imperfect correlations between the data used and actual population change. However, these data adjustments and models have been thoroughly tested, and are further refined and modified through comparison with decennial census benchmarks.

Rounding. Individual counts may not sum to totals due to rounding. Populations are rounded according to size: 0-99 to nearest 5; 100-4,999 to nearest 10; 5,000-9,999 to nearest 25; 10,000 up to 49,999 to nearest 50; 50,000 up to 15 million to nearest 100; and 15 million and over to nearest 1,000.