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Comparing 2009 American Community Survey Data

Subject Area1* 2009 ACS 1-Year,
2007-2009 ACS 3-Year, and
2005-2009 ACS 5-Year with Census 2000
2009 ACS 1-Year with 2008 ACS 1-Year

Age and Sex (01)

Topic 2009 ACS with Census 2000 2009 ACS 1-Year with 2008 ACS 1-Year
Age Compare with Caution

The entire population continually ages into older age groups over time and babies fill in the youngest age group. So, the population of a certain age is made up of a completely different group of people from one time period to the next. Since populations occasionally experience booms/increases and busts/decreases in births, deaths, or migration (for example, the postwar Baby Boom from 1946-1964), one should not necessarily expect that the population in an age group in Census 2000 should be similar in size or proportion to the population in the same age group in different data year(s). For example, Baby Boomers were age 36 to 54 in Census 2000 while they were age 45 to 63 in the 2009 ACS 1-year, between ages 43 to 63 in the 2007-2009 3-year period, and between ages 41 to 63 in the 2005-2009 5-year period. So, the age group 55 to 59 would show a considerable increase in population when comparing Census 2000 data with the single year or multiyear ACS data.  

Compare
Sex Compare

Beginning with the 2008 ACS questionnaire, the layout of the sex question response categories was changed to a horizontal side-by-side layout from a vertically stacked layout on the mail paper ACS questionnaire. For more information on differences in the questionnaire, please see 2007 ACS Grid-Sequential Test

Compare

Race (02)

Topic 2009 ACS with Census 2000 2009 ACS 1-Year with 2008 ACS 1-Year
Race Compare with Caution

The ACS question on race was revised in 2008 to make it consistent with the Census 2010 race question, and this version is used for the 2009 ACS. The change in estimates for 2009 may be due to demographic changes, as well as factors including questionnaire changes, differences in ACS population controls, and methodological differences in the population estimates, and therefore should be used with caution. The 2009 ACS race question is different from the Census 2000 race question, therefore comparisons should be made with caution. 

Do Not Compare (Japanese, Korean, Vietnamese, Other Asian)

An error was discovered in the processing of the 2008 and 2009 ACS data for four of the detailed checkboxes within the Asian category (Japanese, Korean, Vietnamese, and Other Asian). These errors impact the data for the detailed Asian groups and, therefore, comparisons of the 2008 and 2009 estimates should be made with caution. Users may compare estimates for all other groups.  

Hispanic Origin (03)

Topic 2009 ACS with Census 2000 2009 ACS 1-Year with 2008 ACS 1-Year
Hispanic or Latino Origin Compare with Caution

The ACS question on Hispanic origin was revised in 2008 to make it consistent with the Census 2010 Hispanic origin question. Any change, compared with Census 2000, may be due to demographic changes, questionnaire changes, differences in ACS population controls, and/or methodological differences in the population estimates. 

Compare

Ancestry (04)

Topic 2009 ACS with Census 2000 2009 ACS 1-Year with 2008 ACS 1-Year
Ancestry Compare

Ancestry is the only item for which a "not reported" category is published since missing ancestries are never assigned or allocated. The extent of missing ancestry answers was higher in Census 2000 than in the ACS. The difference in the level of response may contribute to the difference in the two distributions. 

Compare

Foreign Born; Citizenship; Year of Entry; Nativity (05)

Topic 2009 ACS with Census 2000 2009 ACS 1-Year with 2008 ACS 1-Year
Citizenship Status Compare Compare
Nativity Compare Compare
Year of Entry Compare

Census 2000 represents data collected as of April 1, 2000 and thus the "2000" year of entry category accounts for the first quarter (Jan-Mar) in 2000 only. The ACS represents data collected throughout the entire year and thus the "2000" year of entry category accounts for the entire year of 2000. 

Compare

Place of Birth (06)

Topic 2009 ACS with Census 2000 2009 ACS 1-Year with 2008 ACS 1-Year
Place of Birth Compare Compare with Caution

Modest changes were made in 2009 to the region and country groupings. Specifically, Macau (code 225) is now included under the definition of China, and Jan Mayen (code 121) and Svalbard (code 135) are included under the definition of Norway, please see 2009 ACS Code List.  

Residence 1 year ago; Migration (07)

Topic 2009 ACS with Census 2000 2009 ACS 1-Year with 2008 ACS 1-Year
Residence 1 Year Ago (Migration) Do Not Compare

The ACS asked for residence 1 year ago whereas Census 2000 asked for residence 5 years ago. 

Compare

Journey to Work; Workers; Commuting (08)

Topic 2009 ACS with Census 2000 2009 ACS 1-Year with 2008 ACS 1-Year
Means of Transportation to Work Compare

The ACS excludes taxicabs in the tabulation category of "public transportation" and includes them in the category "taxicab, motorcycle, bicycle or other means." However, Census 2000 includes taxicabs in the "public transportation" tabulation category. 

Compare
Place of Work Compare Compare
Private Vehicle Occupancy Compare Compare
Time Leaving Home Compare Compare
Travel Time to Work Compare Compare

Children; Household Relationship (09)

Topic 2009 ACS with Census 2000 2009 ACS 1-Year with 2008 ACS 1-Year
Relationship to Householder Do Not Compare

The ACS used a joint relationship/marital status edit and Census 2000 did not. Also, Census 2000 provided more response categories because of a write-in option that was not used in the ACS. Differences in weighting schemes between the census and the ACS could produce inconsistencies in comparisons.

Compare

Grandparent; Grandchildren (10)

Topic 2009 ACS with Census 2000 2009 ACS 1-Year with 2008 ACS 1-Year
Grandparents as Caregivers Compare Compare

Household Type; Family Type; Subfamilies (11)

Topic 2009 ACS with Census 2000 2009 ACS 1-Year with 2008 ACS 1-Year
Household/Family Type Do Not Compare

The ACS used a joint relationship/marital status edit and Census 2000 did not--these edits are used to determine categories of family types. Also, Census 2000 provided more response categories because of a write-in option that was not used in the ACS. Differences in weighting schemes between the census and the ACS could produce inconsistencies in comparisons.

Compare
Subfamilies Do Not Compare

Census 2000 had more detailed relationship categories than were available in the ACS to derive estimates of subfamilies. In addition, the weighting schemes that were used to produce the final estimated numbers of subfamilies were different.

Compare with Caution

The 2009 edit specifications incorporated changes to improve the identification of married-couple subfamilies with children and single-parent subfamilies. The 2009 data show an increase in these family types.  

Marital Status and History (12)

Topic 2009 ACS with Census 2000 2009 ACS 1-Year with 2008 ACS 1-Year
Marital Status Compare

The ACS used a joint relationship/marital status edit and Census 2000 did not. 

Compare
Marital History Do Not Compare

The questions were not asked in Census 2000. 

Compare

Fertility (13)

Topic 2009 ACS with Census 2000 2009 ACS 1-Year with 2008 ACS 1-Year
Fertility Do Not Compare

The question was not asked in Census 2000. 

Compare

School Enrollment (14)

Topic 2009 ACS with Census 2000 2009 ACS 1-Year with 2008 ACS 1-Year
Type of School & School Enrollment Compare

The ACS reference period was 3 months preceding the date of interview, while the Census 2000 reference period was any time since February 1, 2000. 

Compare

Educational Attainment (15)

Topic 2009 ACS with Census 2000 2009 ACS 1-Year with 2008 ACS 1-Year
Educational Attainment Compare Compare
Field of Degree Do Not Compare

The question was not asked in Census 2000. 

Do Not Compare

The question was not asked in 2008 ACS.  

Language Spoken at Home and Ability to Speak English (16)

Topic 2009 ACS with Census 2000 2009 ACS 1-Year with 2008 ACS 1-Year
Ability to Speak English Compare Compare
Language Spoken at Home Compare Compare

Poverty (17)

Topic 2009 ACS with Census 2000 2009 ACS 1-Year with 2008 ACS 1-Year
Poverty Status of Families and People in Families Compare with Caution

The ACS collects data throughout the year on an on-going, monthly basis and asks for a respondent's income over the "past 12 months." Census 2000, however, collected the income data for a fixed period of time -- "during 1999" (the last calendar year). For example, the 2009 ACS 1-year data reflect incomes over 2008-2009, the 2007-2009 ACS 3-year data reflect incomes over 2006-2009, and the 2005-2009 ACS 5-year data reflect incomes over 2004-2009. In a comparison study between Census 2000 income data and the 2000 ACS, income collected in Census 2000 was found to be about 4 percent higher than that in the 2000 ACS. For more information on the differences of income in the ACS and Census 2000, see Income in the American Community Survey:Comparison to Census 2000. For specific questions and answers about sources of poverty data, see Questions and Answers about Sources of Poverty Data [PDF 130K]. 

Compare with Caution

As ACS data are collected every month of the year, adjacent years will have some reference months in common. Hence, comparing the 2009 ACS 1-year with the 2008 ACS 1-year estimates is not an exact comparison of the economic conditions in 2009 with those in 2008. For a discussion of this and related issues, see Hogan, Howard, "Measuring Population Change Using the American Community Survey," Applied Demography in the 21st Century, Steven H. Murdock and David A. Swanson eds., Springer Netherlands, 2008. For specific questions and answers about sources of poverty data, see Questions and Answers about Sources of Poverty Data [PDF 130K].  

Poverty Status of All People in the Poverty Universe Compare with Caution

The ACS collects data throughout the year on an on-going, monthly basis and asks for a respondent's income over the "past 12 months." Census 2000, however, collected the income data for a fixed period of time -- "during 1999" (the last calendar year). For example, the 2009 ACS 1-year data reflect incomes over 2008-2009, the 2007-2009 ACS 3-year data reflect incomes over 2006-2009, and the 2005-2009 ACS 5-year data reflect incomes over 2004-2009. In a comparison study between Census 2000 income data and the 2000 ACS, income collected in Census 2000 was found to be about 4 percent higher than that in the 2000 ACS. For more information on the differences of income in the ACS and Census 2000, see Income in the American Community Survey: Comparison to Census 2000. For specific questions and answers about sources of poverty data, see Income in the American Community Survey: Comparison to Census 2000 [PDF 130K]. 

Compare with Caution

As ACS data are collected every month of the year, adjacent years will have some reference months in common. Hence, comparing the 2009 ACS 1-year with the 2008 ACS 1-year estimates is not an exact comparison of the economic conditions in 2009 with those in 2008. For a discussion of this and related issues, see Hogan, Howard, "Measuring Population Change Using the American Community Survey," Applied Demography in the 21st Century, Steven H. Murdock and David A. Swanson eds., Springer Netherlands, 2008. For specific questions and answers about sources of poverty data, see Questions and Answers about Sources of Poverty Data [PDF 130K].  

Disability (18)

Topic 2009 ACS with Census 2000 2009 ACS 1-Year with 2008 ACS 1-Year
Hearing / vision difficulty Do Not Compare

The 2009 ACS disability questions are different from the Census 2000 disability questions, thus comparisons cannot be made. 

Compare
Cognitive / Ambulatory / Self-care difficulty Do Not Compare

The 2009 ACS disability questions are different from the Census 2000 disability questions, thus comparisons cannot be made. 

Compare
Independent Living difficulty Do Not Compare

The 2009 ACS disability questions are different from the Census 2000 disability questions, thus comparisons cannot be made. 

Compare

Income (Households and Families) (19)

Topic 2009 ACS with Census 2000 2009 ACS 1-Year with 2008 ACS 1-Year
Household and Family Incomes Compare with Caution

The ACS collects data throughout the year on an on-going, monthly basis and asks for a respondent's income over the "past 12 months." Census 2000, however, collected the income data for a fixed period of time -- "during 1999" (the last calendar year). For example, the 2009 ACS 1-year data reflect incomes over 2008-2009, the 2007-2009 ACS 3-year data reflect incomes over 2006-2009, and the 2005-2009 ACS 5-year data reflect incomes over 2004-2009. In a comparison study between Census 2000 income data and the 2000 ACS, income collected in Census 2000 was found to be about 4 percent higher than that in the 2000 ACS. For more information on the differences of income in the ACS and Census 2000, see Income in the American Community Survey: Comparison to Census 2000. The Census Bureau recommends using CPI-U-RS adjustment factors published annually by the Bureau of Labor Statistics (BLS) to adjust 1999 median, mean, and per capita income dollar amounts shown in Summary File 3 to 2009 dollars by multiplying the 1999 dollar amounts by the CPI-U-RS factor of 1.28729056. For CPI-U-RS inflation adjustment factors for other years see: BLS Consumer Price Index. Furthermore, direct comparisons of income and earnings distributions between Census 2000 and the 2009 ACS are not possible due to inflation. Users interested in making distribution comparisons need to inflation adjust individual income records using the Public Use Microdata Samples (PUMS) files from Census 2000.  

Compare with Caution

As ACS data are collected every month of the year, adjacent years will have some reference months in common. Hence, comparing the 2009 ACS 1-year with the 2008 ACS 1-year estimates is not an exact comparison of the economic conditions in 2009 with those in 2008. For a discussion of this and related issues, see Hogan, Howard, "Measuring Population Change Using the American Community Survey," Applied Demography in the 21st Century, Steven H. Murdock and David A. Swanson eds., Springer Netherlands, 2008.  

Sources of Income (households) Compare with Caution

The ACS collects data throughout the year on an on-going, monthly basis and asks for a respondent's income over the "past 12 months." Census 2000, however, collected the income data for a fixed period of time -- "during 1999" (the last calendar year). In a comparison study between Census 2000 income data and the 2000 ACS, income collected in Census 2000 was found to be about 4 percent higher than that in the 2000 ACS. For more information on the differences of income in the ACS and Census 2000, see Income in the American Community Survey: Comparison to Census 2000. The Census Bureau recommends using CPI-U-RS adjustment factors published annually by the Bureau of Labor Statistics (BLS) to adjust 1999 median, mean, and per capita income dollar amounts shown in Summary File 3 to 2009 dollars by multiplying the 1999 dollar amounts by the CPI-U-RS factor of 1.28729056. For CPI-U-RS inflation adjustment factors for other years see: BLS Consumer Price Index. Furthermore, direct comparisons of income and earnings distributions between Census 2000 and the 2009 ACS are not possible due to inflation. Users interested in making distribution comparisons need to inflation adjust individual income records using the Public Use Microdata Samples (PUMS) files from Census 2000.  

Compare with Caution

As ACS data are collected every month of the year, adjacent years will have some reference months in common. Hence, comparing the 2009 ACS with the 2008 ACS estimates is not an exact comparison of the economic conditions in 2009 with those in 2008. For a discussion of this and related issues, see Hogan, Howard, "Measuring Population Change Using the American Community Survey," Applied Demography in the 21st Century, Steven H. Murdock and David A. Swanson eds., Springer Netherlands, 2008.  

Earnings and Income (Individuals) (20)

Topic 2009 ACS with Census 2000 2009 ACS 1-Year with 2008 ACS 1-Year
Per Capita Income, Earnings (people), and Income (people) Compare with Caution

The ACS collects data throughout the year on an on-going, monthly basis and asks for a respondent's income over the "past 12 months." Census 2000, however, collected the income data for a fixed period of time -- "during 1999" (the last calendar year). For example, the 2009 ACS 1-year data reflect incomes over 2008-2009, the 2007-2009 ACS 3-year data reflect incomes over 2006-2009, and the 2005-2009 ACS 5-year data reflect incomes over 2004-2009. In a comparison study between Census 2000 income data and the 2000 ACS, income collected in Census 2000 was found to be about 4 percent higher than that in the 2000 ACS. For more information on the differences of income in the ACS and Census 2000, see Income in the American Community Survey: Comparison to Census 2000. The Census Bureau recommends using CPI-U-RS adjustment factors published annually by the Bureau of Labor Statistics (BLS) to adjust 1999 median, mean, and per capita income dollar amounts shown in Summary File 3 to 2009 dollars by multiplying the 1999 dollar amounts by the CPI-U-RS factor of 1.28729056. For CPI-U-RS inflation adjustment factors for other years see: BLS Consumer Price Index. Furthermore, direct comparisons of income and earnings distributions between Census 2000 and the 2009 ACS are not possible due to inflation. Users interested in making distribution comparisons need to inflation adjust individual income records using the Public Use Microdata Samples (PUMS) files from Census 2000. 

Compare with Caution

As ACS data are collected every month of the year, adjacent years will have some reference months in common. Hence, comparing the 2009 ACS with the 2008 ACS estimates is not an exact comparison of the economic conditions in 2009 with those in 2008. For a discussion of this and related issues, see Hogan, Howard, "Measuring Population Change Using the American Community Survey," Applied Demography in the 21st Century, Steven H. Murdock and David A. Swanson eds., Springer Netherlands, 2008.  

Veteran Status (21)

Topic 2009 ACS with Census 2000 2009 ACS 1-Year with 2008 ACS 1-Year
Period of Military Service Compare

Since Census 2000, the period of military service categories on the ACS questionnaire were updated to: 1) include the most recent period "September 2001 or later;" 2) list all "peace time" periods without showing a date-breakup in the list; and 3) update the Korean War and World War II dates to match the official dates as listed in US Code, Title 38. While the response categories differ slightly from those in Census 2000, data from the two questions can still be compared to one another. 

Compare
Veteran Status Compare

The ACS has two separate questions, whereas in Census 2000, it was a two part question. However, the actual questions remain the same. 

Compare
Service-Connected Disability Status and Ratings Do Not Compare

The question was not asked in Census 2000. 

Compare

Food Stamps (22)

Topic 2009 ACS with Census 2000 2009 ACS 1-Year with 2008 ACS 1-Year
Food Stamp Benefit Do Not Compare

The question was not asked in Census 2000 thus comparisons cannot be made. 

Compare

Employment Status; Work Experience; Labor Force (23)

Topic 2009 ACS with Census 2000 2009 ACS 1-Year with 2008 ACS 1-Year
Employment Status Compare with Caution

The reference periods are different due to year-round ACS data collection. The ACS reference period is the week prior to the respondent completing the interview, or the field representative conducting the interview. Because questionnaires are mailed-out and field interviews are conducted throughout the year, there is a revolving reference period. For Census 2000, the reference period was the week prior to Census Day (April 1, 2000). The Census 2000 Summary File 3 (SF3) labor force data for some places where colleges are located appear to overstate the estimates of people in the labor force, the unemployed, and the percent unemployed because of data capture errors. 

Compare
Hours Worked Compare

The ACS reference period is 12 months preceding the date of interview, while the Census 2000 reference period was the 1999 calendar year. 

Compare
Weeks Worked Compare

The ACS reference period is 12 months preceding the date of interview, while the Census 2000 reference period was the 1999 calendar year. 

Compare

Industry & Occupation; Class of Worker (24)

Topic 2009 ACS with Census 2000 2009 ACS 1-Year with 2008 ACS 1-Year
Class of Worker Compare with Caution

The ACS median earnings Class of Worker tables combine "Unpaid family workers" with "Self-employed in own not incorporated business workers." The Census 2000 tables use different tabulation categories than the ACS. Also, the Census 2000 tables did not include the "full-time, year-round" population and there were no median earnings Class of Worker tables. Thus, comparisons cannot be made for this population or characteristic. 

Compare
Industry and Occupation Compare with Caution

The ACS industry codes are 4-digit codes. The 2005, 2006, and 2007 ACS 1-year data are coded using the 2002 North American Industry Classification System (NAICS) while the 2008 and 2009 ACS 1-year data are coded using the 2007 NAICS. For the 2007-2009 ACS 3-year products and the 2005-2009 ACS 5-year products, the 2002 NAICS codes were mapped to the most equivalent NAICS 2007 code. Census 2000 codes are based on the NAICS 1997 and are 3-digit codes. Codes and descriptions, particularly within the Electronic Shopping, Wholesale, and Information categories changed. 

Compare

Housing (25)

Topic 2009 ACS with Census 2000 2009 ACS 1-Year with 2008 ACS 1-Year
Bedrooms Compare with Caution

A change was introduced in 2008 to the ACS questionnaire regarding Bedrooms. This resulted in differences between the Bedrooms question wording as well as the response option on the 2008 and 2009 question and all pre- 2008 ACS and Census 2000 questionnaires. For more details, see Errata #54

Compare with Caution

Caution should be used when comparing data for Bedrooms between 2008 and 2009. A data processing error was identified for 2008 impacting the "0 bedroom" category. For more details, see Errata #54.  

Contract and Gross Rent Do Not Compare

For Census 2000, tables were not released for total renter-occupied units. The universe in the ACS is "renter occupied" whereas in Census 2000 the universe was "specified renter-occupied housing units," thus comparisons cannot be made. 

Compare
Cost of Utilities Compare Compare
Gross Rent as a Percentage of Household Income Do Not Compare

For Census 2000, tables were not released for total renter-occupied units. The universe in the ACS is "renter occupied" whereas in Census 2000, the universe was "specified renter-occupied housing units," thus comparisons cannot be made. 

Compare
House Heating Fuel Compare Compare
Kitchen Facilities Compare with Caution

Changes made between 2007 and 2008 to the ACS question wording as well as the response option resulted in an increase in the "Lacking Kitchen Facilities" category compared with pre-2008 ACS and Census 2000. For more details, see Errata #53

Compare
Monthly Rent Compare Compare
Mortgage Status Compare

With a mortgage/without a mortgage released in Census 2000 for both total owner-occupied units and specified owner-occupied units. 

Compare
Occupants per Room Compare with Caution

A change was introduced in 2008 to the ACS questionnaire regarding Rooms. This resulted in differences between the Rooms question wording as well as the response option on the 2008 and 2009 question and all pre- 2008 ACS and Census 2000 questionnaires. For more details, see Errata #54

Compare with Caution

Caution should be used when comparing data for Occupants per Room between 2008 and 2009. A data processing error was identified for 2008 impacting the "1 room" category. For more details, see Errata #54.  

Owner Costs as a Percentage of Household Income Compare with Caution

For Census 2000, tables with full distribution were released for total owner-occupied units but medians were not shown. When available, compare like universes. 

Compare
Plumbing Facilities Compare with Caution

Changes made between 2007 and 2008 to the ACS question wording as well as the response option resulted in an increase in the "Lacking Plumbing Facilities" category compared with pre-2008 ACS and Census 2000. 

Compare
Real Estate Taxes Do Not Compare

The universe in the ACS is "owner occupied" whereas in Census 2000, the universe was "specified owner-occupied housing units," thus comparisons cannot be made. 

Compare
Rooms Compare with Caution

A change was introduced in 2008 to the ACS questionnaire regarding Rooms. This resulted in differences between the Rooms question wording as well as the response option on the 2008 and 2009 question and all pre- 2008 ACS and Census 2000 questionnaires. For more details, see Errata #54

Compare with Caution

Caution should be used when comparing data for Number of Rooms between 2008 and 2009. A data processing error was identified for 2008 impacting the "1 room" category. For more details, see Errata #54.  

Selected Monthly Owner Costs Compare with Caution

For Census 2000, tables with full distributions were released for total owner-occupied units but medians were not shown. When available, compare like universes. 

Compare
Telephone Service Compare with Caution

A change was introduced in 2008 to the ACS questionnaire regarding Telephone Service. This resulted in differences between the Telephone Service question wording as well as the response option on the 2008 and 2009 question and all pre- 2008 ACS and Census 2000 questionnaires. For more details, see Errata #53

Compare with Caution

Caution should be used when comparing data for Telephone Service Availability between 2008 and 2009. A data processing error was identified for 2008 impacting the "no" category and underreporting those who did not have telephone service available. For more details, see Errata #53.  

Tenure Compare Compare
Units in Structure Compare Compare
Vacancy Status Compare with Caution

The tabulation category "Rented or sold, not occupied" in Census 2000 is separated into two categories "Rented, not occupied" and "Sold, not occupied" in the ACS. 

Compare
Value of Property Compare with Caution

Unlike Census 2000, the ACS allowed a write-in for values over $250,000 until 2007. Beginning in 2008, value was collected as a continuous variable. For Census 2000, tables with full distribution, medians, and aggregate values were released for both specified owner-occupied units as well as total owner-occupied units. ACS only releases tables for total owner-occupied units. When making comparisons users should compare like universes. 

Compare
Vehicles Available Compare Compare
Year Moved In Compare Compare
Year Structure Built Compare Compare

Group Quarters (26)

Topic 2009 ACS with Census 2000 2009 ACS 1-Year with 2008 ACS 1-Year
Group Quarters Population Compare with Caution

The total group quarters (GQ) population in the ACS may not be comparable with Census 2000 because: 1) There are some Census 2000 GQ types that were out of scope in the ACS such as domestic violence shelters and soup kitchens. Also, there are some Census 2000 GQ type categories that are no longer valid (residential care facility providing "Protective Oversight," hospitals/wards for the chronically ill and hospitals/wards for drug/alcohol abuse). The exclusion of these GQ types from the ACS may result in a small bias in some ACS estimates to the extent that the excluded population is different from the included population. 2) A sample of GQ facilities throughout the United States and Puerto Rico were selected for the ACS. ACS controls the GQ sample at the state level only. Therefore, for lower levels of geography, particularly when there are relatively few GQs in a geographic area, the ACS estimate of the GQ population may vary from the estimate from Census 2000.  

Compare with Caution at National and State level - Do Not Compare below State level

The weighting for the group quarters (GQ) population is controlled at the state level, but not at sub-state levels. For this reason, users may observe greater fluctuations in year-to-year ACS estimates of the GQ population at sub-state levels than at state levels. The causes of these fluctuations typically are the result of either GQs that have closed or where the current population of the GQ is significantly different than the expected population as reflected on the sampling frame. Substantial changes in the ACS GQ estimates can impact ACS estimates of total population characteristics for areas where either the GQ population is a substantial proportion of the total population or where the GQ population may have very different characteristics than the total population as a whole. Users can assess the impact that year-to-year changes in sub-state GQ total population estimates have on the changes in total ACS population estimates by accessing Table B26001 on American Fact Finder. Users should also use their local knowledge to help determine whether the year-to-year change in the ACS estimate represents a real change in the GQ population or may be the result of the lack of adequate population controls for sub-state areas.  

Health Insurance (27)

Topic 2009 ACS with Census 2000 2009 ACS 1-Year with 2008 ACS 1-Year
Health Insurance Do Not Compare

The question was not asked in Census 2000. 

Do Not Compare

Logical coverage edits applying a rules-based assignment of Medicaid, Medicare and military health coverage were added in 2009; please see Applying and Evaluating Logical Coverage Edits to Health Insurance in the American Community Survey for more details. The 2008 tables on American FactFinder do not incorporate these edits and are not comparable to the 2009 tables. 2008 health insurance data at the national, state, county and place levels comparable to the 2009 American FactFinder tables are available at 2008 health insurance rerun tables, in the 2009 ACS 1-year Comparison Profile, and in the 2009 ACS brief "Health Insurance Coverage of Children under Age 19: 2008 and 2009."  

1*Each subject area is listed with its 2-digit code identifier. This code corresponds to the second and third characters of the ACS table number. For example, Table B08303 - Travel Time to Work has the second and third digits of "08" which corresponds to the subject Journey to Work; Workers; and Commuting.


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Source: U.S. Census Bureau | American Community Survey Office | Email ACS | Last Revised: December 04, 2014
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