1 American Community Survey Overview Jerry Wong Information Services Specialist Los Angeles Regional Office U.S. Census Bureau 1/10

2 What is the American Community Survey? A large, continuous survey that: –is sent to 3 million resident addresses per year –produces characteristics of population and housing –produces estimates for small areas and small population groups –Produces characteristics, not a population count –Key component of the decennial census program

History and Timeline of the ACS Continuous measurement conceptualized Congress renewed interest in an alternative to the once-a-decade census Work began on what evolved into the ACS First operational test conducted in 4 sites Test sites expanded yearly to 36 counties in 26 states N=165,000 housing units 2000 N=866,000 housing units in 1,239 counties N=3,000,000 housing units in all counties in 50 states, DC & PR Group Quarters added 2006 First 1-yr estimates released for areas 65, First 3-yr estimates released for areas 20,000+

4 Developing the ACS The ACS was developed to: 1.Focus the Census on improving the population count 2.Provide characteristic data more than once every 10 years to frame policy issues 3.Allow use of current data to respond to new trends

5 Decennial Census Census 2000 used 2 forms 1.“short” form – asked for basic demographic and housing information, such as age, sex, race, how many people lived in the housing unit, and if the housing unit was owned or rented by the resident 2.“long” form – collected the same information as the short form but also collected more in-depth information such as income, education, and language spoken at home Only a small portion of the population, called a sample, received the long form.

6 Census 2000 and ACS Similarities Many questions similar Many of the same basic statistics are released Comparisons can be made for most population and housing subjects 5-year estimates will be produced for same broad set of geographic areas –including census tracts and block groups, zip code tabulation areas

7 Census 2000 and ACS Key Differences ACS data now available for larger and mid-sized areas ACS data for small geographic areas and population groups will be produced every year starting in 2010 ACS data describe a period of time and published data are based on 12 months, 36 months, or 60 months

8 Census 2000 and ACS Data Quality Goal of the ACS: Produce data of comparable quality to Census 2000 long form ACS 5-year data –Sampling error is larger in ACS due to smaller sample size –Non-sampling error is smaller due to: Lower rate of nonresponse Higher item response rates Permanent interviewing staff using automated data collection

Census and the ACS 2010 CensusACS U.S. population count U.S. population characteristics Short form only Includes short form questions Only long form is for U.S. territories, except Puerto Rico Conducted in Puerto Rico “Usual residence” rule“Current residence” rule

10 American Community Survey Content 10

11 Social Characteristics Education Marital Status Fertility Grandparent Caregivers Veterans Disability Status Place of Birth Citizenship Year of Entry Language Spoken at Home Ancestry/Tribal Affiliation

12 Economic Characteristics Income Benefits Employment Status Occupation Industry Commuting to Work Place of Work

13 Housing Characteristics Tenure (own vs. rent) Occupancy & Structure Housing Value Taxes & Insurance Utilities Mortgage/Monthly Rent

14 Demographic Characteristics Sex Age Race Hispanic Origin

15 Recent Content Changes New Content Health Insurance Coverage 2.Veteran’s Service-connected Disability 3.Marital History Field of Undergraduate Degree Wording and format changes in 2008 to match Census 2010 questions

Content Changes Three new questions –Health Insurance Coverage –Veteran’s Service-connected Disability –Marital History Deletion of one question –Time and main reason for staying at the address Changes in some wording and format

17 ACS Sample Design Sample is accumulated over TIME to produce lowest levels of geographic detail to replace census sample 5 years of data are required for areas and population groups with less than 20,000 population Sample cases selected from an updated Master Address File (MAF)

18 Sample Questionnaires mailed to about 1 in 480 addresses each month throughout the U.S. and Puerto Rico. 1 in 40 addresses per year (2.5% of the population). Average of addresses per month per congressional district. Total of 3 million addresses each year, or 250,000 per month. Inclusion of population in group quarters beginning in 2006.

19 Target Population Resident population of the United States and Puerto Rico Living in housing units and group quarters (group quarters added in 2006) Current residents at the selected address

20 Methodology Sample includes about 3 million addresses each year Three modes of data collection –mail –phone –personal visit Data are collected continuously throughout the year

21 Operations MailTelephonePersonal Visit

22 Period Estimates Describe the average characteristics over a specific period of time Contrast with point-in-time estimates – Do not describe the characteristics on a specific date Period is 1 year, 3 years, or 5 years for ACS

23 Geographic Boundaries Multiyear estimates are based on geographic boundaries as of January 1 of the last year in the multiyear period Example: ACS estimates use boundaries as of Jan 1, 2008 Boundaries of other statistical areas will be updated every decade in conjunction with the decennial census 2010 Census boundaries will be used for data released in 2011

24 ACS Data Release Schedule Hypothetical situation: If Census 2010 contained a long form, detailed characteristic data would not be available until 2012

25 ACS Data Products Profiles –Data Profiles –Narrative Profiles –Comparison Profiles –Selected Population Profiles Tables –Detailed Tables and Collapsed Tables –Subject Tables –Ranking Tables –Geographic Comparison Tables Thematic Maps Public Use Microdata Sample (PUMS) Files

ACS Data for Geographic Areas in Hawaii Geography Year Data 65,000+ Population Year Data 20,000+ Population StateHawaii Hawaii; In various metro or micropolitan statistic areas Hawaii; Urban Hawaii; Rural CountyHawaii County Honolulu County Maui County Hawaii County Honolulu County Maui County Kauai County PlaceHonolulu CDP Hilo CDP Kahului CDP Kailua CDP Kaneohe CDP Kihei CDP Mililani Town CDP Pearl City CDP Waimalu CDP Waipahu CDP School DistrictHawaii Department of Education

ACS Data for Geographic Areas in Hawaii Geography Year Data 65,000+ Population Year Data 20,000+ Population Metropolitan or Micropolitan Statistical Area Hilo, HI Micropolitan Statistical Area Honolulu Metropolitan Statistical Area Kahului-Wailuku, HI Micropolitan Statistical Area Hilo, HI Micropolitan Statistical Area Honolulu Metropolitan Statistical Area Kahului-Wailuku, HI Micropolitan Statistical Area Kapaa, HI Micropolitan Statistical Area Urban AreaHonolulu, HI Urbanized Area Kailua (Honolulu Co.)—Kaneohe, HI Urbanized Area Honolulu, HI Urbanized Area Kailua (Honolulu Co.)--Kaneohe, HI Urbanized Area Hilo, HI Urban Cluster Kahului HI Urban Cluster Kailua (Hawaii Co.)--Holualoa, HI Urban Cluster Kihei, HI Urban Cluster Pukalani—Makawao—Haiku—Pauwela, HI Urban Cluster Congressional District Congressional District 1 Congressional District 2 Congressional District 1 Congressional District 2 Public Use Microdata Area (PUMA) PUMA , PUMA , PUMA , PUMA , PUMA , PUMA , PUMA , PUMA , PUMA

28 Using the Data: Factors to Consider Universe and residence rules Time Periods Reference Periods

29 Residence Rules The American Community Survey uses a “two-month” rule Decennial census based upon the concept of “usual residence”

30 Residence Rules Resident of a housing unit if a person: - Lives there year round - Lives there more than 2 months but not year round - Is living there now with no other place to live - Is away now for 2 months or less Not a resident of a housing unit if a person: - Lives there 2 months or less with another residence - Is away now for more than 2 months

31 Period Estimates Describes the characteristics of an area over a specific period of time Contrasts with point-in-time estimates that describe the characteristics of an area on a specific date 1-year, 3-year, and 5-year estimates are released for geographic areas that meet specific population thresholds

32 Reference Periods ACS uses the interview date as the single reference point, or as the end of single reference point, or as the end of a reference period, for all data collection. a reference period, for all data collection.

33 Questions With No Specific Reference Period Most ACS questions do not stipulate a period of time that should be referenced Interpretation is yearly average since the data are collected each month and averaged across months

34 Questions With a Specific Reference Period Relative to Interview Date Other questions specify a period of time relative to the date of interview Interpretation is still a yearly average but covering a slightly different period of time than the calendar year

35 Group Quarters Place where people live or stay that is normally owned or managed by an entity or organization providing housing or services for the residents. Two types of group quarters: 1. Institutional 1. Institutional 2. Non-institutional 2. Non-institutional Group Quarters Population includes all people not Group Quarters Population includes all people not living in households. living in households. - - This term includes those people residing in group. quarters as of the date the ACS was conducted.

36 Overview of ACS Timeline Overview of ACS Timeline First year of data collection for full sample in Data for calendar year 2007 released beginning in August Annual data for geographic areas over 65,000 population. 3 year averages are now available for geographic areas 20,000 to 65, year averages for geographic areas under 20,000 in 2010.

37 Timeline ACS Data single year collection (e.g. 2007) is closed out just after the beginning of a calendar year (e.g. 2008) Single-year and multiyear data products start to become available in the summer of the same year. For example 2007 ACS estimates were released in 2008 The cycle repeats EVERY year

Release Schedule for ACS Data Release Schedule for ACS Data

39 Understanding Estimates and Margin of Error

40 Estimates ACS data are estimates ACS data are not counts of the population or housing Population counts are produced from the decennial census - Counts are updated throughout the decade through the Population Estimates Program

41 Margin of Error (MOE) Margin of Error Definition:Margin of Error Definition: A measure of the precision of an estimate at a given level of confidence (90%, 95%, 99%) A measure of the precision of an estimate at a given level of confidence (90%, 95%, 99%) –MOEs at the 90% confidence level for all published ACS estimates Confidence Interval Definition:Confidence Interval Definition: A range that is expected to contain the population value of the characteristic with a known probability. A range that is expected to contain the population value of the characteristic with a known probability.

Margin of Error

43 Interpreting Margin of Error Indicates that a data user can be 90 percent certain that the estimate and the population value differ by no more than the value of the MOE MOE can help data users assess the reliability of an estimate MOE can help data users avoid misinterpreting small differences between estimates as significant

44 American Community Survey: Multiyear Data

45 Population Thresholds for ACS Estimates 1-year estimates 3-year estimates 5-year estimates 65,000 + people XXX 20,000+ people XX Less than 20,000 people X

46 Constructing Multiyear Estimates Data are pooled across 36 or 60 months Data are weighted to produce estimates Estimates are controlled for age, sex, race, and Hispanic origin Multiyear estimates are not an average of 1-year estimates

47 Use Multiyear Estimates When … No 1-year estimate is available Margins of error for 1-year estimates are larger than required Analyzing data for small population groups

48 Currency vs. Reliability CurrencyReliability 1-year estimates provide information based on the last year Larger sample sizes produce estimates that are more statistically reliable 3-year estimates provide information based on the last year and the 2 years before that 3-year estimates are based on 3 times as many sample cases as 1-year estimates 5-year estimates provide information based on the last year and the 4 years prior 5-year estimates are based on 5 times as many sample cases as 1-year estimates

49 Inflation Adjustment Dollar-valued data items are inflation adjusted to the most recent year for the periodDollar-valued data items are inflation adjusted to the most recent year for the period Income, rent, home value, and energy costsIncome, rent, home value, and energy costs Adjusted using inflation factors based on the Consumer Price Index (CPI)Adjusted using inflation factors based on the Consumer Price Index (CPI) Adjustment designed to put the data into dollars with equal purchasing powerAdjustment designed to put the data into dollars with equal purchasing power

50 Geographic Boundaries Multiyear estimates are based on geographic boundaries as of January 1 of the last year in the multiyear periodMultiyear estimates are based on geographic boundaries as of January 1 of the last year in the multiyear period Boundary Annexation Survey collects boundary changesBoundary Annexation Survey collects boundary changes Boundaries of other statistical areas will be updated every decade in conjunction with the decennial censusBoundaries of other statistical areas will be updated every decade in conjunction with the decennial census

51 Population Controls Estimates of housing units and people are controlled to the population estimates derived from the Population Estimates ProgramEstimates of housing units and people are controlled to the population estimates derived from the Population Estimates Program Multiyear estimates are controlled to the average of the individual year’s estimates for the periodMultiyear estimates are controlled to the average of the individual year’s estimates for the period

52 Using multiyear Estimates to Make Comparisons? Comparing Across Geographies Only compare the same type of estimate 1-year estimates to other 1-year estimates 3-year estimates to other 3-year estimates 5-year estimates to other 5-year estimates Same time period

53 Comparing Across Time Periods Same geographic area –Use caution if geographic boundaries have changed over time –Easier to compare non-overlapping periods –Make comparisons using the same length time period

54 Overlapping Periods

55 American Community Survey Learning More ACS Main Page 2008 Data Release Page Data Product Details Guidance on Comparing 2008 ACS 1-Year Data Guidance on Comparing ACS 3-Year Data to Other Sources Geographic Overview User Notes Errata Sheets Design and Methodology Report The ACS Compass Products

American Community Survey Accessing Home Page

American Community Survey ACS Main Page

58 American Community Survey 2008 Data Release

59 American Community Survey Data Product Details

American Community Survey Data Product Details - Hawaii

61 American Community Survey Geography Overview

62 American Community Survey Comparing 2008 ACS 1-Year Data

63 American Community Survey Comparing ACS 3-Year

64 American Community Survey User Notes

65 American Community Survey Errata

66 American Community Survey Subject Definitions

67 American Community Survey Using Multiyear Estimates

68 American Community Survey Question by Question Fact Sheet

American Community Survey Question by Question Fact Sheet Health Insurance

70 American Community Survey Design and Methodology Report Important reference document covering methods used in producing ACS data Available at

71 The ACS Compass Products A Compass for Understanding and Using American Community Survey Data General Data Users Businesses High School Teachers Congress Federal Agencies Media PUMS State and Local Governments Puerto Rico Community Survey (PRCS) Researchers Rural Areas American Indian and Alaska Native Populations Planned Puerto Rico Community Survey (PRCS) – in Spanish

72 The ACS Compass Products A Compass for Understanding and Using American Community Survey Data Fully scripted PowerPoint presentations – An Overview of the ACS – Things that May Affect the Estimates – Understanding Multiyear Estimates – Data Products – Geographic Areas and Concepts – Introduction to the PUMS files E-learning ACS Tutorial (forthcoming)

73 For more information Subscribe to “ACS Alert” Visit the ACS/PRCS website: Contact by telephone: Contact by

74 U.S. Census Bureau Partnership & Data Services Program Sherman Way, Suite 400 Van Nuys, CA (888) Toll Free (888) Toll Free L.A. Regional Website: L.A. Regional Website: Resources: Need Assistance?