Social Explorer; U.S. Census Bureau; American Community Survey 2010 Summary File: Technical Documentation.
|1-Year Estimates||3-Year Estimates||5-Year Estimates|
|Published for selected geographic areas with populations of 65,000 or greater||Published for selected geographic areas with populations of 20,000 or greater|
No population thresholdand published for small geographic areas
|Represent the average characteristics over a calendar year||Represent the average characteristics over the 3-year period of time||Represent the average characteristics over the 5-year period of time|
|Have fewer published geographic areas than the 3-year and 5-year estimates||Have fewer published geographic areas than the 1-year estimates but less than the 5-year estimates||Have more published areas than the 1-year and 3-year estimates|
|1-year estimates||3-year estimates||5-year estimates|
|12 months of collected data||36 months of collected data||60 months of collected data|
|Data for areas with populations of 65,000+||Data for areas with populations of 20,000+||Data for all areas|
|Smallest sample size||Larger sample size than 1-year||Largest sample size|
|Less reliable than 3-year or 5-year||More reliable than 1-year; less reliable than 5-year||Most reliable|
|Most current data||Less current than 1-year estimates; more current than 5-year||Least current|
|Best used when||Best used when||Best used when|
Currency is more important than precision
Analyzing large populations
More precise than 1-year, more current than 5-year
Analyzing smaller populations
Examining smaller geographies because 1-year estimates are not available
Precision is more important than currency
Analyzing very small populations
Examining tracts and other smaller geographies because 1-year estimates are not available
For more information on the ACS estimates, users are encouraged to visit the ACS website www.census.gov/acs/www/guidance_for_data_users/estimates/.
The following special data values can appear in the ACS Summary File table as an explanation for the absence of data:
- Missing Value = ""
- Dot = "."
- Zero = "0"
- Negative 1 = "-1"
Jam Values for Medians
The following is a listing of the jam values for medians. For example, if there is an estimate of "2499" for table B10010, then it does not indicate a dollar amount. It means that the median is somewhere below 2,500 and thus isn't calculated.
|Jam Value||Actual Meaning||Use for Medians|
|0||1 or less||Age, Duration of Marriage|
|9||9.0 or more||Rooms|
|10||10.0 or less||Gross Rent as Percentage of Income, Owner Costs as Percentage of Income|
|50||50.0 or more||Gross Rent as Percentage of Income, Owner Costs as Percentage of Income|
|99||100 or less||Rent, Gross Rent, Selected Monthly Owner Costs, Monthly Housing Costs|
|101||101 or more||Duration of Marriage|
|116||115 or more||Age|
|199||200 or less||Tax|
|1001||1,000 or more||Selected Monthly Owner Costs|
|1939||1939 or earlier||Year Built|
|1969||1969 or earlier||Year Moved In|
|2001||2,000 or more||Rent, Gross Rent|
|2005||2005 or later||Year Built, Year Moved In|
|2499||2,500 or less||Income, Earnings|
|4001||4,000 or more||Selected Monthly Owner Costs, Monthly Housing Costs|
|9999||10,000 or less||Value|
|10001||10,000 or more||Tax|
|200001||200,000 or more||Income|
|250001||250,000 or more||Income, Earnings|
|1000001||1,000,000 or more||Value|
There are a few special rules on how certain margin of error are determined for ACS estimates. The accuracy of the estimate (decimal place) within the detailed tables determines how many digits the margin of error is rounded.
The only exceptions to these rules are tables B19082 (Shares of aggregate household income by quintile) and B19083 (index of income inequality, commonly known as GINI). B19082 has estimates rounded to one decimal place and MOE rounded to two decimal places. B19083 has estimates rounded to three decimal places and MOE rounded to four decimal places.
Every base table consists of a series of estimates. If more than half the estimates are not statistically different from 0 (at a 90 percent confidence level), then the table fails. Each estimate is subject to sampling variability that is summarized by its standard error. Dividing the standard error by the estimate yields the coefficient of variation (CV) for each of the estimates. (If the estimate is 0, a CV of 100 percent is assigned.) To implement this requirement for each table at a given geographic area, CVs are calculated for each of the table's estimates, and the median CV value is determined. If the median CV value for the table is less than or equal to 61 percent, the table passes for that geographic area; if it is greater than 61 percent, the table fails. Tables that are too sparse will fail this test. In that case, the table will not be published for that geographic area. Whenever a table fails, a simpler table that collapses some of the detailed lines together can be substituted for the original, more detailed table. The rules are then applied to the simpler table. If it passes, the simpler table is released. If it fails, none of the estimates for that particular table is released for this geographic area. These rules are applied to single-year period estimates and multi-year period estimates based on three years of sample data.
|US/State-only Sequences - Missing PR Data||PR Only Sequences - Missing US/State Data|
|1 (US)||169 (PR)|
|2 (US)||170 (PR)|
|23 (US)||171 (PR)|
|24 (US)||172 (PR)|
|25 (US)||173 (PR)|
|28 (US)||174 (PR)|
|29 (US)||175 (PR)|
|30 (US)||176 (PR)|
|31 (US)||177 (PR)|
|32 (US)||178 (PR)|
Therefore, for sequences 167-179 for areas other than Puerto Rico, the sequence files exist, but they are blank.
Tables That Are Contained in More Than One Sequence File
|Table ID||Table Title||Sequences|
|B24010||Sex By Occupation For The Civilian Employed Population 16 Years And Over||107, 108|
|B24020||Sex By Occupation For The Full-Time, Year-Round Civilian Employed Population 16 Years And Over||114, 115|
|B24121||Detailed Occupation By Median Earnings In The Past 12 Months For The FullTime, Year-Round Civilian Employed Population 16 Years And Over||126, 127, 128|
|B24122||Detailed Occupation By Median Earnings In The Past 12 Months For The FullTime, Year-Round Civilian Employed Male Population 16 Years And Over||129, 130, 131|
|B24123||Detailed Occupation For The Full-Time, Year Round Civilian Employed Population 16 Years And Over||132, 133, 134|
|B24124||Detailed Occupation For The Full-Time, Year Round Civilian Employed Male Population 16 Years And Over||135, 136, 137|
|B24125||Detailed Occupation For The Full-Time, Year Round Civilian Employed Male Population 16 Years And Over||138, 139, 140|
|B24126||Detailed Occupation For The Full-Time, Year Round Civilian Employed Female Population 16 Years And Over||141, 142, 143|
The last six tables on the list are only produced at the United States national level (summary level 010), and the files for these sequences will be blank for all other summary levels.