Department of Finance
915 L Street
Sacramento, CA 95814

E-2. California County Population Estimates and Components of Change by Year — July 1, 2000–2008

December 2008

OFFICIAL STATE ESTIMATES

Acknowledgments

Linda Gage produced the state and county estimates and prepared this report. Mary Heim contributed expert consultation and insights into the estimating methods and data sets. Melanie Martindale produced the birth projections. Douglas Kuczynski collected and prepared the group quarters data. Evaon Schnagl produced the school enrollment projections and prepared the driver's license address change data. Walter Schwarm validated input data, formulas and methodologies used in the current state and county estimates series.

Suggested Citation

State of California, Department of Finance, California County Population Estimates and Components of Change by Year, July 1, 2000-2008. Sacramento, California, December 2008.

• Press Release (.doc, <5 MB)
• E-2. California County Population Estimates and Components of Change by Year — July 1, 2000–2008 (.xls, <1 MB)

Contents

This report presents provisional state and county population estimates for July 1, 2008; revised estimates for July 1, 2000 through July 1, 2007; and components of population change by year for fiscal years 1999-00 through 2007-08.

Highlights

California’s population surpassed 38 million by July 1, 2008 according to official population estimates released by the State Department of Finance. the growth of 1.16 percent, representing 436,000 new residents during the fiscal year, continued the pattern of modest growth rates over the past few years.

Natural increase remains the primary source of the state’s growth since 2002. the natural increase of 329,000 in the past year is composed of 571,000 births minus 242,000 deaths. This accounted for 75 percent of the 2008 fiscal year growth. Net migration contributed over 107,000 new residents, 25 percent of the growth. Net migration includes all legal and unauthorized foreign immigrants, residents who left the state to live abroad, and the balance of hundreds of thousands of people moving within the United States both to and from California. During the fiscal year, the state gained over 242,000 new foreign immigrants and, similar to the prior four years, experienced a modest loss of 135,000 persons to other states.

Since the last national census on April 1, 2000, the state has grown by almost 4.3 million persons for an overall growth rate of 12.6 percent. the population was increased by 4.5 million births and the arrival of 1.8 million foreign immigrants and diminished by 1.9 million deaths and the net overall loss of 84,000 domestic migrants. Natural increase during the period was over 2.6 million accounting for 60 percent of the growth. Net migration contributed 1.7 million persons.

Methodology

The state and county populations are independently estimated using population change models benchmarked on official decennial census counts. The state population is estimated using the Driver License Address Change method. County population proportions are estimated using the average of three separately estimated sets of proportions. The final distribution of proportions is applied to the independently estimated state control.

State Estimate. The state population is estimated using the Driver License Address Change (DLAC) Method. This composite method separately estimates the population under age 18, 18 through 64, and 65 years and older. Administrative records such as births, deaths, driver license address changes, tax return data, Medicare and Medi-Cal enrollment, immigration reports, elementary school enrollments, and group quarters population are among the data used in this method. All data are in summary tables and do not reveal the identity of any individual.

County Estimates. County population proportions result from averaging three methods.

DLAC Method. A modified version of the state Driver License Address Change (DLAC) method is used for counties. County proportions of the state total result from changes in county population values for births, deaths, school enrollment, foreign and domestic migration, medical aid enrollments, and group quarters population.

Ratio-Correlation Method. This method models change in household population as a function of changes in the distributions of driver licenses, school enrollments, housing units, and deaths. Estimates of county group quarters are added.

Tax Return Method. County proportions are derived by the U.S. Census Bureau using matched federal income tax returns to estimate inter-county migration along with vital statistics, group quarters, and other information for the population aged 65 and over.

Data Considerations

Sources. Data used in estimation models come from administrative records of 17 state and federal departments and agencies. Timeliness and coverage in these series vary. Corrections, adjustments or estimates may be made while preparing the estimates.

Accuracy. Data and models used to produce population estimates are subject to both measurement and nonmeasurement errors. This results in imperfect correlation between the data used to estimate the population and actual population change. the data and estimating models have been thoroughly tested with decennial census results that provide benchmarks for the estimates series. Compared to the 2000 decennial census counts for California's counties, results of the estimation models differed by an average of 1.9 percent. The total state estimate was within one-half of one percent (0.5%) of the decennial census count. Data and methods are further refined and modified throughout the decade.