Since 1999, through a series of both annual and multiyear contracts, WRMA has completed numerous demographic task orders for the County of Los Angeles, having done work involving various levels of geography ranging from census blocks to the total county and including customized geographies. The topics have included estimates and projections of population, poverty, income, health insurance status, food stamp program participation, TANF program participation, hospital bed availability, educational attainment, jury-eligible persons, and minority language voters. Most of the reports have age, race/ethnicity, and gender breakdowns. In March 2006, WRMA was awarded a new five-year contract to continue this work. Two examples of this work are included below.
Los Angeles County Department of Health Services
WRMA prepares for the Los Angeles County Department of Health Services (DHS) annual demographic estimates with five-year projections at the census tract level. Most years the demographic variables include population, poverty, and heath insurance status by age, gender, and race/ethnicity. The base data are from the latest decennial census and WRMA updates these with tract data on births, deaths, licensed drivers, and registered voters. WRMA also uses in the updates county-level school enrollment trends and data from the Census Bureau's Current Population Survey and American Community Survey. The county- and city-level estimates from the California Department of Finance, Demographic Research Unit also are used. An external validity check is accomplished by making comparisons to the annual Bureau of the Census population estimates for counties. The population estimates are used by DHS in calculating mortality and morbidity rates for its health assessment reports.
Los Angeles County Board of Supervisors
WRMA, as part of the Los Angeles County's 2001 Redistricting Work Group, provided technical support to the county's Boundary Review Committee. WRMA tasks were to 1) aggregate 2000 Census data into a manageable set of racial/ethnic categories appropriate for Los Angeles County from an original set of 143 racial/ethnic fields; 2) construct a report of demographic profiles for existing and proposed supervisory districts; and 3) create detailed population estimates by age, race/ethnicity, and gender using 2000 Census data, birth records, death records, school enrollments, driver license files, voter registration files, and the Bureau of the Census Current Population Surveys.
Los Angeles County Department of Public Social Services
In 2005 WRMA prepared estimates and projections for Los Angeles County’s Department of Public Social Services concerning families in poverty with children under age 18, persons eligible for but not in the MediCal program, and persons eligible for but not in the food stamps program. The time period covered was 1999 through 2005, and our estimates were based on Los Angeles data from the Bureau of the Census Current Population Surveys. We calculated the percent eligible population using poverty status, age, parent status, and citizenship status. For more stable estimates of the total population trends in the County, we used estimates from the California Department of Finance (DOF), Demographic Research Unit. To obtain the number of food stamp eligible persons, the DOF population estimates were multiplied by the CPS percentages. We compared our county estimates to State level estimates of MediCal and food stamp program eligibility made by other researchers and found our estimates to be reasonably similar given that Los Angeles County has a higher poverty level and a higher percentage of non-citizens and undocumented persons.
Los Angeles County Community Development Commission
From 2002 to 2003, WRMA updated the Los Angeles County Community Development Commission’s Strategic Plan data on population, race/ethnicity, female-headed households, “special needs” groups, overcrowding, and educational level. The data were summarized at the census tract, city/community, and supervisory district levels. WRMA used data from a special 2000 Census tabulation to produce for the Community Development Commission a census block group level report on low and moderate income families, persons with disabilities, and population characteristics for census block groups. The data were aggregated by political jurisdictions and used in the allocation of community development grants.
Los Angeles County Registrar Recorder County Clerk
In 2003 the Los Angeles County Registrar Recorder County Clerk (RRCC) requested that WRMA make estimates of the number of citizens age 18 and older who have English language limitations. RRCC needed the data at the census tract level and grouped by the language spoken at home. We analyzed the data needs and ordered a 2000 Census special tabulation file from the Census Bureau based on questions from the “long form” questionnaire. From the special tabulation file WRMA created a user-friendly database and a county level summary report.
Los Angeles County Decennial Census Local Review Team
WRMA has assisted the County in its local review and supplementing of the decennial census address and boundary files (MAF/TIGER) for the 2000 and 2010 censuses. This has entailed comparing census address files with addresses from the County’s voter files, driving license files, assessor files and counts from previous censuses. Boundary files were compared to County assessor boundary files, Thomas Brother boundary files, and previous census boundary files. WRMA also participated in the County decennial reviews concerning the splitting, merging, and modifying of census block, tract, and Public Use Microsample Areas (PUMAS). WRMA has worked with the County’s team to improve the decennial counts through public outreach on the fiscal and social significance of the enumeration. We have worked with the County to analyze the census differential undercounts and to promote methods of adjusting for the undercount.
Los Angeles County Boundary Review Committee
WRMA was part of the County's 2001 Redistricting Work Group that provided technical support to the County's Boundary Review Committee to comply with the Federal Voting Rights Act to assure fair and effective representation for racial and language minority groups. WRMA's specific assignments were to 1) create a manageable set of race/ethnicity categories appropriate for Los Angeles County—the 2000 Census redistricting data set contained 139 racial/ethnic fields; 2) aggregate block-level population data to files with census tract-city geography; 3) prepare documentation for the data files and for the race/ethnicity category decision; and 4) present these issues and data to the Work Group and the Boundary Review Committee.
