1. Census Basics UP206A: Introduction to GIS

2. History When was the first census? – 1790 How many people were counted? – 3.9 million How many states did we have then? – 13 original states, plus the districts of Kentucky, Maine, Vermont, and the Southwest Territory What questions were asked? – name of head of family – number of persons in each household of the following descriptions: free White males 16 years and upward, free White males under 16 years, free White females, all other free persons (by sex and color) and slaves

3. Census 2000 When was it taken? – April 1, 2000 How many people were counted? – 281,421,906 (13.2 percent increase over the 248,709,873 in 1990) Questionnaire included seven questions for each household: – name – sex – age – relationship – Hispanic origin – race – owner/renter

5. Census 2010 When was it taken? – April 1, 2010 How many people were counted? – 308,745,538 (9.7 percent increase over the 281,421,906 in 2000) Questionnaire included ten questions for each household: – http://2010.census.gov/2010census/about/interactive- form.php http://2010.census.gov/2010census/about/interactive- form.php Release schedule

7. Why is the census important? Census data directly affect how more than $400 billion per year in federal funding is allocated to local, state and tribal governments – $3 trillion over a decade. census determines how the 435 seats in the U.S. House of Representatives are divided among the 50 states

8. How is this money spent? Better infrastructure. More services. A brighter tomorrow for everyone. In fact, the information the census collects helps to determine how more than $400 billion dollars of federal funding each year is spent on infrastructure and services like: Hospitals Job training centers Schools Senior centers Bridges, tunnels and other-public works projects Emergency services

9. SHORT AND LONG… Before 2010…

10. Short: how many?

11. Long: how we live When was the long form introduced? – 1940 census How many people got the long form? – 17 percent of the households (1 out of every 6 households) What questions were asked? – ancestry – income – mortgage – size of the housing unit – disability – etc

13. What? No more long form? Meet the American Community Survey The form Replaces the long form – ie, [old long form] = [new American community survey] From once in 10 years, to every year! (started in 2005) 1, 3, and 5 year estimates – Which to choose? – http://www.census.gov/acs/www/guidance_for_data_u sers/estimates/ http://www.census.gov/acs/www/guidance_for_data_u sers/estimates/ You are in luck… the data is JUST becoming available, just in time for your final projects

14. Summary File 1 counts and basic cross-tabulations of information collected from all people and housing units. – race, age, household size, owner/renter Lowest level geography: – Blocks

15. Summary File 3 contains tables with social, economic and housing characteristics compiled from a sample of approximately 19 million housing units (about 1-in-6 households) that received the Census 2000 long-form questionnaire. Many tables are given for nine major race and Hispanic or Latino groups. Lowest level geography: – Block Groups/Census Tracts

16. Census Geography UP206A: Introduction to GIS

20. Counties Counties in 48 States Independent Cities in 4 States Parishes in Louisiana Cities and Boroughs in Alaska 58 58 counties in California 3,141 3,141 counties in the US

21. Places Incorporated Places (i.e. municipalities) Census Designated Places (i.e. unincorporated areas) 1,081 1,081 places in California 25,150 25,150 places in the US

22. Census Tracts Relatively homogenous population characteristics 4,000 Size: optimally 4,000 people, range between 1,000 and 8,000 2,054 2,054 census tracts in Los Angeles County 65,344 65,344 census tracts in the US

23. Block Groups Groups of blocks (share the same first digit) Smallest areas for which sample data available 1,500 Size: optimally 1,500 people, but range between 300 to 3,000 6,351 6,351 block groups in Los Angeles County 208,689 208,689 block groups in the US

24. Blocks Smallest units of data tabulation Cover the entire nation Do not cross census tracts or counties Generally bounded by visible features and legal boundaries 100 Size: average about 100 people 89,614 89,614 blocks in Los Angeles County 8.2 million 8.2 million blocks in the US

25. Urbanized Areas Densely settled areas with population of at least 50,000 Geographic core of block groups or blocks that have a population density of at least 1,000 people per square mile – Urban Cluster www.census.gov/geo/www/ua/ua_2k.html

26. ZCTA’s ZCTAs: ZIP Code Tabulation Areas Approximate area representations of USPS ZIP Code service areas Based on Census 2000 blocks To address difficulties in mapping USPS ZIP Codes May represent either a five or three-digit USPS ZIP Code http://www.census.gov/geo/ZCTA/zcta.htm l http://www.census.gov/geo/ZCTA/zcta.htm l

27. ZCTA’s How ZIP Code Tabulation Areas Are Created Determine the majority ZIP Code for each census block with addresses.

28. FIPS FIPS – Federal Information Processing Standards 06 037 701400 4 STATECOUNTY CENSUS TRACT BLOCK GROUP

29. Tiger Files Topologically Integrated Geographic Encoding and Referencing developed at the U.S. Census Bureau to support its mapping needs for the Decennial Census and other Bureau programs coverage of the United States, Puerto Rico, the U.S. Virgin Islands, American Samoa, Guam, the Commonwealth of the Northern Mariana Islands, and the Midway Islands http://www.census.gov/geo/www/tiger/

30. Data and Census Geography The larger the census geographic unit, the greater the amount of data available (i.e. Single years of data by County) The smaller the census geographic unit, the less data available (i.e., Age in five- year categories for Census Tracts)