Transcript Data from the Census Bureau: Censuses, Surveys & Tools

Census 2010: Accessing Census
Data
THURSDAY, July 21, 2011
10-11:30am
Quick Review
2010 decennial data is “short-form” only – demographic
characteristics; ACS now source of “long-form” type of data
Census Data released in two “flavors” –
Aggregate Data
Microdata
A third type of data product identifies geographic boundaries
Aggregate Data released in a variety of products, differing in
content, geographic specificity and temporal coverage
Microdata has flexibility of individual level information, but
balances this by only gross geographic detail
Access and Resources
Aggregate data resources
Microdata resources
Geography resources
Documentation resources
Visualization resources
Local resources
Access and Resources
Aggregate resources:
Current: American Factfinder, DataFerrett, Uexplore/Dexter
Historical: NHGIS, ICPSR, Historical Census Browser
Microdata resources
Online Analysis: SDA & IPUMS
Extract/Download: IPUMS, ICPSR, NBER, DataFerrett, Census
Geographic: Census, MABLE/Geocorr, IPUMS
Documentation: IPUMS, AFF2, ICPSR
Visualization: Social Explorer
Local Resources: DOF/DRU, SDC’s, UC DATA, DataLab
Aggregate Data Resources
The “old” American Factfinder
The “new”
American Factfinder
Alternative to AFF:
FTP Full Files
Same FTP
Options for
ACS
Historical Census
Data Browser
Micro-data Resources
Survey Documentation
and Analysis (SDA) and
the Integrated Public
Use Microdata Samples
(IPUMS)
The Integrated Public Use Microdata Samples
The Integrated Public Use Microdata Samples
www.ipums.org at the Minnesota Population Center
IPUMS-USA
Harmonized data on people in the U.S. census and American
Community Survey, from 1850 to the present.
IPUMS-CPS
Harmonized data on people in the Current Population Survey,
every March from 1962 to the present
Important!
Harmonized: Questions asked change over time: How to make
data comparable?
Integrated: Multiple data collections & surveys simultaneously
available
Microdata: The underlying individual-level data is available,
not just pre-defined tables.
The American Community Survey and
the Current Population Survey
CPS – Long-running monthly survey (dating back to the 1940’s)
focused on labor force characteristics (unemployment,
earnings, hours worked).
~ 55,000 sample HH’s, multiple interviews, personal
In addition to the basic monthly questions, additional modules
are “piggy-backed” onto the survey to provide more depth on
particular topics. Most widely used supplement is the Annual
Social and Economic Supplement (ASEC) - aka Annual
Demographic Survey or the March Files. (~100,000 HH’s)
In-depth survey – lots of detail about sources of income, work,
occupational, hours, etc. (as well as core demographic
information on race/ethnicity, nativity, age, sex, educataion)
The American Community Survey and
the Current Population Survey
ACS – “New” continuous survey, replaces the long form of the
decennial census, first fully implemented in 2005 (noninstitutionalized) and 2006 (institutionalized).
~ 2,000,000 HH’s annually, mixed mail-in/personal interviews
Substantial overlapping content with CPS
Broader range of content, somewhat less detail
Larger sample sizes allow for greater geographic detail
The American Community Survey and
the Current Population Survey
Microdata
Aggregate
vs.
The Integrated Public Use Microdata Samples
www.ipums.org at the Minnesota Population Center
Strengths:
Tremendous centralized documentation
Many “value-added” data items
Wonderful extraction engine (if downloading data)
Multiple statistical Packages supported
Online Analysis also possible
The Integrated Public Use Microdata Samples
Online Analysis
Links
The Basics of SDA
What is SDA?
What can you do with SDA?
The parts of the SDA interface
• Menu
• Variable List
• Active variables
• Analysis Specification
But…
Before we go live….
Part II. Working with SDA
1. Parts of the SDA interface
2. Finding data/variables/subjects
- search
- documentation
3. Analysis Components - rows, columns, selection, controls
Procedures - crosstabs, means, correlations
4. Aids in Analysis
Recoding
Saving new variables
Downloading
The Basics of SDA
What is SDA?
SDA (Survey Documentation and Analysis) is a set of programs
for the documentation and Web-based analysis of survey data.
It was developed and is maintained by the Computer-assisted
Survey Methods Program (CSM) at UC Berkeley.
It was developed as a companion program with CASES (Computer
Assisted Survey Execution Program), a package for collecting
survey data based on structured questionnaires, using a variety
of modes of data collection.
It operates on a transposed file structure, which makes analysis
of datasets, especially large datasets, extremely fast.
Part I. The Basics of SDA
What is SDA?
SDA (Survey Documentation and Analysis) is a set of programs
for the documentation and Web-based analysis of survey data.
It was developed and is maintained by the Computer-assisted
Survey Methods Program (CSM) at UC Berkeley.
It was developed as a companion program with CASES (Computer
Assisted Survey Execution Program), a package for collecting
survey data based on structured questionnaires, using a variety
of modes of data collection.
It operates on a transposed file structure, which makes analysis
of datasets, especially large datasets, extremely fast.
Part I. The Basics of SDA
What data is available in SDA?
LOTS!
Many popular social science datasets (e.g. the GSS, the ANES, the
PUMS from the Decennial Census, the ACS, the CPS Annual
Demographic Files,…… can be found in SDA format.
Many archives (ICPSR, IPUMS, CPANDA, Roper, SDA, UCDATA….)
provide at least some of their holdings in SDA format.
Multiple Census Samples at IPUMS
(http://usa.ipums.org/usa/sda/)
And CPS (March files) data, as well
(http://cps.ipums.org/cps/sda/)
The Basics of SDA
What can you do with SDA?
SDA can be used to:
•
learn about a dataset (metadata, paradata)
•
search for variables of interest
•
investigate sample sizes and variable distributions
•
perform statistical analyses
•
transform, manipulate and create variables for each unit
•
extract and download subsets or full datasets
Part I. The Basics of SDA
The four parts of the SDA
interface
• Action Menu
• Variable List
• Active Variable
• Analysis Specification
Action Menu
Collapsed Variable Tree
Active Variables
Analysis Specification
2. Finding data/variables/subjects
Online SDA codebook
IPUMS detailed documentation
Working with SDA
Analysis –
Components - rows, columns, selection, controls
Procedures - crosstabs, means, correlations
Screens will vary depending upon what procedure you are using.
Start with exploratory – frequencies, cross-tabulations
The variables you are interested in
Who to include in the table
Part II. Working with SDA
Aids in Analysis
Recoding
Saving new variables
Downloading
Recoding variables – on the fly
Can be used in row, column, control (Crosstabs)
age (5-18)
age (r: 5-18)
age (d: 5-18)
age (c:13,5)
age (c:st,w)
Selects, but does not collapse
Selects AND Collapses
Collapses, but does not select
Collapses into categories of width w
starting with value st
Recoding variables
– Web interface
Question 1: Use the CPS or ACS?
Question 2: What is the desired level of analysis (person, family,
household)?
Question 3: Who should be excluded?
(How to limit to family households, or only
particular age groups, or….?
DataFerrett Content
Geographic Resources
Social Explorer
ACS, 2010 Census
Selected Data Resources at
Berkeley
Library Data Lab
http://sunsite3.berkeley.edu/wikis/datalab/
SDA (Survey Documentation & Analysis)
http://sda.berkeley.edu/
Statewide Database
http://swdb.berkeley.edu/
California Census Research Data Center
http://www.ccrdc.ucla.edu/
The Econometrics lab
http://emlab.berkeley.edu/data2.shtml
Thomas J. Long Business & Economics Library
http://www.lib.berkeley.edu/BUSI/electres.html
Questions/Comments
email me at: [email protected]
http://ucdata.berkeley.edu