An Introduction to the American Community Survey 5-Year Data Release Webinar: December 8, 2010 Release Day: December 14, 2010 Call-in Information Toll free number: Participant passcode: CENSUS

Introductions Frank Ambrose Chief, State and Governmental Programs Branch, Customer Liaison and Marketing Services Office Sharon Stern Assistant Division Chief, Project Coordination, Communication, and Data User Support, ACS Office Scott Boggess Chief, ACS Coordination Staff, Housing and Household Economic Statistics Division 2

Measuring America American Community Survey –Sept. 28: Year Estimates –Dec. 14: Year Estimates –Jan.: Year Estimates –Jan.: Year PUMS files (public use microdata files) 2010 Census –By Dec. 31: 2010 Census Apportionment Counts –Feb. – March: State and Local Level Data –2010 Census Results Released Throughout 2011 and beyond Demographic Analysis –Dec. 6 3

What is the ACS? A large, continuous survey that: samples approximately 3 million addresses per year produces characteristics of population and housing produces estimates for small areas and small population groups 4

ACS is Part of the 2010 Decennial Census Program Focus the 2010 Census and future decennial censuses on improving the population count and collecting only basic characteristics Eliminate the long form and implement the ACS to provide detailed characteristic data more than once every ten years 5

6 ACS Estimates Are NOT the 2010 Census Population Counts The 2010 Census counts the population to support apportionment and redistricting. The ACS supplements this information with annually updated data on the nations population and housing characteristics. The purpose of the ACS is not to count every person in a community or town but rather, to provide a portrait of the communitys characteristics.

7 History of the ACS First data released for nation and areas 250,000+ Demonstation Period: evaluated operational feasibility and survey quality Expanded to full sample of HUs in all counties in 50 states, DC & PR GQs added First 1-yr est. released for areas more than 65,000 First 3-yr. est. released for areas more than 20,000 First 5-yr. est. released for areas of all sizes Implemented new and modified content to meet emerging need.

8 Content of the ACS More than 30 Federal agencies participate in the Interagency Committee for the ACS which provides oversight for the content of the survey. As part of the decennial census program, survey content is limited to those measures required by Federal agencies

ACS Topics 9 Housing Chatacteristics –Housing Value –Utilities Social Characteristics –Education –Language Spoken at Home Economic Characteristics –Income –Occupation Demographic Characteristics

ACS Topics Meeting the Need More than $400 billion dollars are allocated based on Census data, including the ACS Even more agencies need the data for planning and evaluation Example: Under the Voting Rights Act, data on languages spoken at home are needed to assess the fairness of voting practices in governmental subdivisions. 10

ACS Data Collection 11 MailTelephonePersonal Visit

Period Estimates The estimates are NOT an average of 1-year estimates Describe the average characteristics over a specific period of time Period estimates do not represent a single point in time Period is –1 year (12 months) –3 years (36 month) –5 years (60 months) 12

ACS Data Dissemination: 1-Year, 3-Year, and 5-Year Estimates 13

Map of ACS Publication Areas 14

ACS 1-Year Estimates Available for Counties with Populations 65,000 or more 15

All Geographies Available Percentage with Published ACS Estimates 1-Year3-Year5-Year United States100 State, DC, Puerto Rico100 County or equivalent Place (incorporated places and census designated places) Unified School District Census Tract

Sample Period Estimates: Percentage of People 5 years and older Speaking Only English at Home Rockland County, NY 17 Year Estimate Type Year (+/- 2.2) 67.7 (+/- 2.1) 64.1 (+/- 2.1) 3-Year (05-07) 67.2 (+/- 1.1) 3-Year (06-08) 66.8 (+/- 1.2) Source: U.S. Census Bureau, 2005 through 2009 American Community Surveys

Characteristic with year-to-year increases * Artificial data for illustrative purposes only. 18

Characteristic with annual fluctuations (increases and decreases) * Artificial data for illustrative purposes only. 19

Characteristic with little change over time * Artificial data for illustrative purposes only. 20

Details on the 5-year release What is included? Types of Tables Detailed tables Data profiles Narrative profiles Subject tables Geographic comparison tables Text Files Summary files Public Use Microdata Sample (PUMS) files 21 Available now: 5-year Data Product Preview Page

Check out the details online 22

Data and Documentation Navigation 23

Updates, Contact Information, FAQs 24

Detailed Tables for the ACS 5-Year Estimates 25

Details on the 5-year release How do I download the tables? American FactFinders familiar tools. –View on screen then choose to download to a presentation format or a database compatible format. –Go directly to the AFF Download Center to select tables and geographies, then download text files Tables not included on AFF –Pre-packaged in summary files for download –Select tables available on the FTP site in.csv format –Technical documentation will be available for experienced users to download and read the files with statistical software –Select tools will be available to assist less experienced users 26

AFF Download Options 27

12/14/2010 Where do I find the tables? 28 First Stop: American FactFinder Second Stop: ACS 5-Year Data Page –Some tables are available on the FTP site as comma delimited.csv files –All estimates are available in summary files –ACS website will tell you where to go

29 Strength of the ACS Produces reliable characteristic estimates for geographies and subpopulations The ACS generally does a better job estimating percents, rates, means, and medians than it does totals

30 Making Comparisons The ACS facilitates comparisons across geographies or subpopulations for the same survey period Users should not mix 1-year, 3-year, and 5-year ACS estimates when making comparisons The ACS and the Census 2000 sample survey are different surveys, estimates from the two are not always comparable

31 Guidance on Comparing ACS and Census 2000 Quick Guide – Simple topic by topic recommendations for making comparisons; what you SHOULD do Comparison Guidance – More detailed explanation of how differences in the two surveys impact comparability Table Comparison Tool – Helps you locate comparable ACS and Census 2000 Detailed Tables

32 Comparing Across Geographies The 5-year ACS release includes two products to help users make comparisons across geographies –Geographic Comparison Tables (GCTs) –Thematic Maps 72 different characteristics Can compare across States, Counties, Places, Metropolitan and Micropolitan Statistical Areas, Combined Statistical Areas, Congressional Districts, Urban/Rural Areas, Urbanized Areas, PUMAs, School Districts, and American Indian Areas/Alaska Native Areas/Hawaiian Homelands/Alaska Native Regional Corporations

33 County Map pdfs To assist you in working with the data we produced several high-quality, county-level maps for both the ACS and Census 2000 These maps are higher resolution versions of the Thematic Maps on American FactFinder Unlike the pdf maps, the Thematic Maps are customizable

Example of a Census 2000 Map 34

35 Quality of ACS Estimates Recent research suggests that margins of error around ACS 5-year estimates will be about 1.75 times as large as those associated with the Census 2000 sample estimates Evaluations after Census 2000 demonstrated reductions in ACS nonsampling error relative to Census 2000

36 Margins of Error and Data Filtering We do not perform any data quality filtering for the 5-year ACS estimates Check margins of error to ensure estimates have sufficient reliability for their intended use You can improve the reliability of estimates by aggregating geographies or subpopulations

Example of Aggregating Estimates GeographyEstimateMargin of Error Tract 15,2641,624 Tract 26,5081,395 Tract 34,3641,026 Tract 46,8651,909 Apply the formula: New Estimate = 23,001 (Equal to the sum of estimates) New Margin of Error = 3,046 (Less than the sum of MoEs) The estimates in this example are fictitious.

All Data At Once, New Data Every Year Unlike Census 2000 which released data on a rolling basis, ACS is releasing data for all geographies at once Data are being released much quicker than Census 2000 data, within a year of the completion of data collection All geographies will now get new ACS data every year, rather than once a decade 38

Question and Answer Session Questions after the Webinar Contact Your Respective Liaisons 39