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American Community Survey
- 1. American Community Survey KrisKasianovitz Libbie Stephenson Christine Wells January 13, 2008
- 2. What is theAmerican Community Survey (ACS) • A survey conducted by the US Bureau of the Census • Conducted every year since 2003 • Focuses on a sample of the population • Collects data on the US population on demographic, social, economic and housing characteristics • Helps communities determine where to locate services and allocate resources
- 3. What topics doesthe ACS contain? • Comparable to the decennial census • Basic demographics – Age, race, sex, mar stat – Birthplace, citizenship, language spoken, disabilities, migration, children, employment, income, occupation, poverty, vet status, education • Housing – Type, age, value, facilities, utilities, ownership, mortgage/rent, telephone, car ownership See: http://www.census.gov/acs/www/SBasics/SQuest/SQuest1.htm
- 4. How is thedata collected? • Mail questionnaire to a sample of 3 million addresses (250,000 per month) • Follow-up by telephone and in-person • Cumulated over 1, 3 and 5 years • Rolling sample – collected throughout the year • One year of data is a 2.5% sample – 5 years of data results in a 12.5% sample
- 5. Counting People inthe US • Decennial Census • Population Estimates • American Community Survey Comparing the ACS to other sources. See: http://www.census.gov/acs/www/UseData/compACS.htm
- 6. Deciding which datayou need • Total number/exact count of people • Estimates of the number of people • Exact count population/housing characteristics • Estimates on population and housing characteristics
- 7. 7 ACS Geographic AreaTypes U.S. and Puerto Rico Type of Data Population Size Type of Geographic Area Years Available Annual estimates 250,000 or more States 2003 -> Annual estimates 65,000 or more States Congressional Districts Public Use Microdata Areas *Metropolitan Areas *Urban Areas 1 2006 -> 3-year averages 20,000 or more States Congressional Districts Public Use Microdata Areas *Metropolitan Areas *Urban Areas 2 2008 -> 5-year averages 600 or more States Congressional Districts Public Use Microdata Areas *Metropolitan Areas *Urban Areas Tracts Block Groups 2009-> 1. 53.6 % MA’ s and 10.8% UA’s included 2. 96.8 % MA’s and 23.4 % UA’s included 01/29/15 Public Affairs workshop
- 8. ACS Geography • Availabilitydepends on population size of the geographic area • Availability changes depending on 1, 3 and 5 year averages • Short time span -> larger geog units • Longer time span -> more geog detail
- 9. How the datais updated • In 2010 … • Areas with 65,000 or more – 1-year average beginning 2009 – 3-year average 2007-2009 – 5-year average 2005-2009 • Areas with 20,000 to 64,999 – 3-year average 2007-2009 – 5-year average 2005-2009 • Areas with less than 20,000 – 5-year average 2005-2009 • In 2011 … – All averages will be updated by one year. Ex. 5-year average will cover 2006-2010 and so on.
- 10. What can youmeasure with the ACS? • Average household size • Population density • Fertility • School drop out rate • Home ownership rate, Homeowner vacancy rate • Housing affordability • Income inequality, per capita income, income-to- poverty ratios • Migration
- 11. To Consider • Timeperiod • Geography • Topics • Population or housing totals
- 12. For more information… • Tauber, Cynthia. American Community Survey for Community Planning. 2006. • American Community Survey. Design and Methodology Report http://www.census.gov/acs/www/Downloads/tp67.pdf • Accuracy of the Data http://www.census.gov/acs/www/UseData/Accuracy/Accura cy1.htm • Overview of geography http://www.census.gov/acs/www/UseData/geo.htm
Editor's Notes
- #4Â Show them that you can download the questionnaires from the link on the slide. http://www.census.gov/acs/www/SBasics/SQuest/SQuest1.htm
- #6 So, you have probably all heard of the Census – what is this ACS and how does it relate to the Census? One of the ways you may have done research with data is to use the resources produced by the US Bureau of the Census. You are probably all pretty familiar with the Census. Ask: how many people have used census data in a class project or in research? Census: The Census is conducted every ten year and asks very basic questions about household composition, and the age, race and ethnicity of each household or group quarters. It is considered to be a “complete count” of the US population. The Census is mandated by law in order to determine the state-by-state representation in the congress. You should use census data when your research calls for using data Population Estimates: Since the Census is conducted once every 10 years, there can be a need for more up to date information. Both the ACS and the population estimates data provide inter-censal information. The population estimates provide only estimates on the number of people in counties of the US, using an estimation model containing head counts from the most recent census, number of births and deaths, and net migration into or out of a county. Keep in mind that this set of materials provides only an estimate of the total population and does not contain other contextual details. American Community Survey: The ACS provides estimates – it does not count people, but it contains similar information as is contained in the Census and it contains many other details on characteristics of the population.
- #7 Official source for a complete count is the decennial census and the population estimates If you just need characteristics then the ACS is a good choice. Basic demographics are in the decennial census and more recent ACS will supplement Estimates on complete counts are in the population estimates at the county level – to be used in between the decennial census !!! Numbers and totals among census, ACS and estimates cannot be compared!!!! Different population groups, sampling, weighting, changes in what and how questions are asked.
- #8 This chart shows you the type of data you can get whether it is annual, 3-year or 5-year averages, what the population size is of the geographic area available, and what specific geographic tabulations are available. The last column to the right tells you the years for which the data are available. Keep in mind that for the each set of estimates the geography becomes more detailed. This is possible because the number of people included increases; privacy and confidentiality can be preserved. Also, although MA’s and UA’s are indicated in the mix, not all are included – again to preserve privacy and confidentiality and to ensure a representative sample.
- #9 The ACS sample is collected from what is called the Master Address File – and it is updated when alerted to new housing or changes in housing by the US Postal Service. The shorter the amount of time covered by the ACS estimates (annual, 3-year, or 5-year averages) the larger the geographic units; the longer the time span, the more geographic detail.
- #10Â The idea of this rolling average will provide more recent information and will allow more flexibility in analysis.
- #11Â These are just some of the kinds of topics you can study with the ACS
- #12Â To decide which part of the ACS, population estimates or census you need to consider what it is your research needs. You have to look at the charts on what is available, what geography is included, what topics you want and how many people you need to work with. Review the Research continuum and research question that Kris K covered.