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2 Introduction: Public Use Microdata Sample (PUMS) Files American Community Survey (ACS) Microdata Files Metropolitan Areas – Old and New

HSUG-West, Berkeley, 9/25/03 3 Where Does Census Housing Data Come From? Decennial Census data comes from both the short-form (100%) and the long-form questionnaires (~1-6 households sample). With regard to housing, the short form yields only tenure and occupancy data. The long form has 21 (some are multi-part) questions concerning housing.

HSUG-West, Berkeley, 9/25/03 4 Number of Housing Tables in Census 2000 Summary Files: Summary File 1 Summary File 2 Summary File 3 Summary File

HSUG-West, Berkeley, 9/25/03 5 What is PUMS Data? Public Use Microdata Sample files contain a sample of individual housing unit and person records from the census, along with sample weights. There are two released PUMS samples – 1% and 5%. The 1% file has more detailed characteristics. The 5% offers more geographic detail.

HSUG-West, Berkeley, 9/25/03 6 What Housing Data does PUMS contain? Tenure Units in Structure Occupancy Status Housing Value Gross Rent Rooms, Bedrooms Age of Structure Plumbing, Kitchen Facilities, Vehicular, and Telephone Availability Year Householder Moved into Unit Property Taxes Paid Cost of Utilities Cost of Fuels Acreage Rent Mortgage Status Second Mortgage Status Property Insurance

HSUG-West, Berkeley, 9/25/03 7 Why Use PUMS? Summary vs. detail information Predefined tables vs. custom tabulations Restricted variables vs. full range of available responses Greatest possible detail while still ensuring confidentiality

HSUG-West, Berkeley, 9/25/03 8 Census Public-Use Microdata Samples History 1960 Census - 1% sample created as a prototype 1970 Census - 1% sample introduced as a standard product 1980 Census – 1% and 5% samples 1990 Census - 1% and 5% samples 2000 Census – 1% and 5% samples

HSUG-West, Berkeley, 9/25/03 9 PUMS Geography PUMS data is available only for a specially delineated set of geographies, PUMAs (5%) and super-PUMAs (1%). PUMAs have a minimum of 100,000 population, super-PUMAs 400,000. Super-PUMA and PUMA boundaries do not cross state lines. PUMAs fit within super-PUMAs. Boundaries are drawn with some input from the states and local area.

HSUG-West, Berkeley, 9/25/03 10 California has 62 super-PUMAs and 235 PUMAs. California’s 2000 PUMAs

HSUG-West, Berkeley, 9/25/03 11 PUMS California Geography In California, PUMA boundaries were constructed to follow city lines, where possible. Example: PUMA = Fullerton City in Orange County. This holds less true for San Diego County and the San Francisco Bay Area Counties, as local input often chose to use tract boundaries. Super-PUMA/PUMA boundaries and county boundaries frequently coincide.

HSUG-West, Berkeley, 9/25/03 12 S.F. Bay Area PUMAs We are in PUMA 02403

HSUG-West, Berkeley, 9/25/03 13 Microsample Areas are Designated With a Code: Super-PUMAs (1%) have a 5 digit code, with the first 2 digits as the state FIPS code. Example: (Solano and Napa Counties) (California’s FIPS Code = ’06’). Range is – PUMAs (5%) also have a 5-digit code. In California, PUMA (5%) codes are lowest in the north, and highest in the southern part of the state. Range is – PUMA codes are unique within the state, but may be repeated in other states.

HSUG-West, Berkeley, 9/25/03 14 Where do I get PUMS data? PUMS data is available free of charge in downloadable form from the US Census Bureau: A DVD of the data will be available from the Census Bureau in Fall, In addition to the data it will include the Beyond 20/20 software for accessing the data. DataFerret also provides online access to PUMS data:

HSUG-West, Berkeley, 9/25/03 15 The American Community Survey (ACS) Microdata Microdata sample files are also currently available for the and ACS data. The technical documentation, record layout, geographies, and content will not be same! But the same principles for generating custom tabulations will hold true. ACS sample sizes are much smaller. Expect a tradeoff in accuracy vs. timeliness when deciding whether to use decennial or ACS PUMS data. When using PUMS, please be sure to cite both the census source (decennial or ACS) and the data year.

HSUG-West, Berkeley, 9/25/03 16 ACS Microdata for California ACS coverage has slowly expanded over time. The first tabulations available are for should be the first year for which ACS has complete coverage of the US. The first California counties covered by the program were San Francisco and Tulare in has tabulations for 21 California counties has tabulations for 24. More counties were sampled than tabulated, however. The 2000 and 2001 ACS microdata files for California have no county-level detail. For more information, please see:

HSUG-West, Berkeley, 9/25/03 17 Metropolitan Statistical Areas – What They Were, What They Are Metropolitan Statistical Area: “A geographic entity, defined by the Federal OMB for use by Federal statistical agencies, based on the concept of a core area with a large population nucleus, plus adjacent communities having a high degree of economic and social integration with that core.”

HSUG-West, Berkeley, 9/25/03 18 Changes The standards have changed 6 times since 1950, and so the definitions (lists of areas) for presenting metropolitan area statistics have changed 10 times since The June 30, 1999 definition is used for Census 2000 products. There is a new definition as of June 6, 2003, which will be applied to future Census Bureau products. The changes over time in areas defined as “Metropolitan” mostly reflect population growth, not changes in the defined concept.

HSUG-West, Berkeley, 9/25/03 19 The Way Things Were – 1999 Definitions: 3 CMSAs 12 PMSAs 12 MSAs

HSUG-West, Berkeley, 9/25/03 20 Core Based Statistical Area (CBSA) Classification A CBSA consists of the county or counties associated with at least one core of 10,000 or greater population, plus adjacent counties having a high degree of social and economic integration with the core(s) as measured by commuting ties. Core Based Statistical Areas Population in a Core Metropolitan Statistical Areas 50,000 or more Micropolitan Statistical Areas 10,000 to 49,999 Territory not included in a CBSA is designated as Outside Core Based Statistical Areas. Core Based Statistical Areas Population in a Core Metropolitan Statistical Areas 50,000 or more Micropolitan Statistical Areas 10,000 to 49,999 Territory not included in a CBSA is designated as Outside Core Based Statistical Areas.

HSUG-West, Berkeley, 9/25/03 21 CBSA Building Blocks Counties and equivalent entities throughout the United States and Puerto Rico Counties and equivalent entities throughout the United States and Puerto Rico

HSUG-West, Berkeley, 9/25/03 22 CBSA Cores Central counties are those counties that: have at least 50% of their population in urban areas (UAs or UCs) of at least 10,000 population; or have within their boundaries a population of at least 5,000 that is located in a single urban area of at least 10,000 population Central counties are those counties that: have at least 50% of their population in urban areas (UAs or UCs) of at least 10,000 population; or have within their boundaries a population of at least 5,000 that is located in a single urban area of at least 10,000 population

HSUG-West, Berkeley, 9/25/03 23 Aggregating Counties Commuting data are used to qualify outlying counties. A county qualifies as an outlying county if: at least 25 percent of the employed residents of the county work in the CBSA’s central county or counties, or at least 25 percent of the jobs in the county are accounted for by workers residing in the CBSA’s central county or counties A county qualifies as an outlying county if: at least 25 percent of the employed residents of the county work in the CBSA’s central county or counties, or at least 25 percent of the jobs in the county are accounted for by workers residing in the CBSA’s central county or counties Measures of settlement structure, such as population density and the percentage of population that is urban, are not used to qualify outlying counties.

HSUG-West, Berkeley, 9/25/03 24 Divisions of Metropolitan Statistical Areas Metropolitan Statistical Areas containing at least one core with a population of 2.5 million or greater may be subdivided to form Metropolitan Divisions A county will be identified as a main county of a Metropolitan Division if: 65 percent or more of its employed residents work within the county, and the ratio of the number of jobs located within that county to its number of employed residents is at least A main county automatically serves as the basis for forming a Metropolitan Division.

HSUG-West, Berkeley, 9/25/ Metro Standards 33 CBSAs, of which: 7 Micropolitan Areas and 26 Metropolitan Areas, of which: 6 are multi-county.

HSUG-West, Berkeley, 9/25/03 26 Learn More About PUMS CENSUS 2000 Main Page: CENSUS 2000 Support Pages: CENSUS Electronic Products Support Pages:

HSUG-West, Berkeley, 9/25/03 27 Learn More About Metropolitan Areas CENSUS Metropolitan Areas Intro Page: area.htm.

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