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American Community Survey (ACS)

Questions & Answers - American Factfinder 2

October 11, 2011

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Category A. American Community Survey (ACS) General

Q: How do we calculate "minority population" from census data given the fact that "Hispanic" population is not included in race and still is considered minority population?
A: There are tables on Hispanic/Not Hispanic by Race. You can get non-Hispanic White population from those tables to calculate "minority population". In the Census 2010 Summary File 1, Table P11 (Hispanic or Latino, and not Hispanic or Latino by Race for the Population 18 Years and over) gives non-Hispanic White population.

Q: Is it true that the 5-year datasets have the lowest margin of error (MOE)?
A: 5-year data have smaller MOEs compared with annual ACS and 3-year ACS data because the sample is larger after accumulating surveys over a 5 year period. But MOEs of 5-year ACS are still much larger compared to Census 2000 long form data. MOEs for small geographies such as block groups and census tracts can be very large due to the small sample in ACS.

Q: I can't find disability data in ACS. Is this correct?
A: The disability definitions and questions have changed since 2000, and changed again in 2008. Because of these changes, the disability data are only available in the 1-year file (as of November 2011). The new 3-year (2008-2010) file will include disability tables for geographic units meeting the 20,000 population threshold.

Q: Do disability data include data on impaired hearing or impaired sight?
A: Yes. The ACS disability data have tables with hearing and vision difficulties. For ACS 2010, Table B18102 is Sex by Age by Hearing Difficulty and Table B18103 is Sex by Age by Vision Difficulty.

Q: Can you estimate persons or households in Poverty by using household income? For example, all households that make less than $18,000.
A: Poverty is a complex measure based on household size, income, children and adults over 65. It is not just based on income.

Category B. American Factfinder 2 (AFF2)

Q: What is the schedule for moving prior year ACS data to AFF2?
A: The Census Bureau is having trouble moving the prior year data into AFF2 so the timeline is indefinite.

Q: Are block group data available in the AFF?
A: Block group level data for the ACS 5-year data are not available in the AFF and are only downloadable via DataFerrett or the Census Bureau FTP site. 2010 decennial Census block group data are available in AFF2. The DataFerrett website is http://dataferrett.census.gov/. There is a document called "DataDerrett Tutorial" that can be downloaded from the "Census and AFF Resources" area in the recorded webinar.

Q. On the AFF2 home page, the left column includes the categories "Population Groups" and "Industries Code." What is the difference?
A: "Population Groups" represent categories based on race, and ethnicity. For example, if you are interested in information on the Asian population alone, you could get tables associated with "Asian" from "Population Groups". "Industries Code" is associated with economic data, and would provide more detailed information on specific types of industry.

Q: Where can you get the table lists so that you can search by table number in the "Quick Start" box?
A: http://www.census.gov/acs/www/guidance_for_data_users/comparing_2009/

Q: Is there a maximum number of records you can download from AFF2?
A: Yes. The AFF2 only allows 10 tables at a time. The maximum geography is 10,000 records, and the limit on the total number of data rows by geographies by tables is 500,000.

Q: Is there some kind of hierarchy of tables, so you can scan through logically? Scrolling through all these categories looks pretty overwhelming.
A: Under "Topics" and then under "Product Type" in the AFF2 home page, there are choices of detailed tables, subject tables and profiles etc. similar to the old AFF. You can also try the "Quick Start" box.

Q: I was using "Topic" search to look for data for 10 different summary levels on 10 tables and was dismayed to discover I could not save my query terms.
A: You might have better success if you stick to simple queries and join the data outside of AFF2 after downloading.

Q: Are shape files available in AFF2?
A: No. Shape files are only available through the Census Bureau geography website.
http://www.census.gov/geo/maps-data/data/tiger-line.html

Q: Must we specify tables before we specify geography?
A: No, there is no particular order you have to follow when using the new AFF. You can select geography first.

Q: Can we save the query and share the query link with others in the AFF2?
A: No. You can only save your "Table View" page and share tables with others. AFF2 does not support saving queries.

Q: Tables in Excel format downloaded from the AFF2 are not in numeric format and all numbers are in character format, resulting in left justified values. In addition, Excel files do not include "GEOID" as field. What should we do?
A: You can select "download data as CSV files". CSV files will give you the GEOID column and give right justified numbers.

Q: The Census Bureau has released processing code in SAS and Excel extraction software. Are there any plans to do release code in R?
A: Unfortunately, the Census Bureau does not have plans for release in R format.

Category C. Other

Q: Who hosted AFF2 webinar at October 11, 2011?
A: FHWA hosted the webinar and invited the Census Bureau staff, Michelle Jiles to present.

Q: Summary File 3 (SF3) of Census 2000 was also from a sample survey, but it did not include MOEs. Why do we have MOEs in ACS?
A: Census 2000 SF3 didn't provide MOEs to users although MOEs for Census 2000 SF3 can be calculated using the documentation provided here: http://www.census.gov/prod/cen2000/doc/sf3.pdf. With ACS, the Census Bureau decided to make the MOEs explicit.

Q: Is the Longitudinal Employer-Household Dynamics (LEHD) equivalent to the "Journey to Work"?
A: LEHD data are from administrative records and are not survey data. The LEHD currently does not include self-employed or federal workers. LEHD data provide a link between a worker "home" address and a business address which might be an imputed work location. Users should use LEHD with caution because of several potential issues including failure to capture employment dispersion. Please read the NCHRP report to understand more about LEHD limitations. http://onlinepubs.trb.org/onlinepubs/nchrp/docs/NCHRP08-36(98)_FR.pdf

Q: What is the link to DataFerrett?
A: The DataFerrett website is http://dataferrett.census.gov/. There is a document called "DataFerrett Tutorial" that can be downloaded from the "Census and AFF Resources" area in the recorded webinar.

Q: Why doesn't the Census Bureau use legacy AFF if there are so many complaints about AFF2?
A: The Census Bureau has decided it will NOT go back to the legacy version of AFF.

Updated: 07/29/2013
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