Documentation: ACS 2006 -- 2008 (3-Year Estimates)
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Publisher: U.S. Census Bureau
Document: ACS 2008-3yr Summary File: Technical Documentation
citation:
Social Explorer; U.S. Census Bureau; American Community Survey 2006-2008 Summary File: Technical Documentation.
ACS 2008-3yr Summary File: Technical Documentation
Appendix J: User Notes
1) Jam Values

Some data values represent unique situations where either: a) the information to be conveyed is an explanation for the absence of data, represented by a symbol in the data display, such as "(X)", or b) the information to be conveyed is an open-ended distribution, such as 115 or greater, represented by 115+.

Following are the special data values (and their meaning) for case (b), which can appear in any 2008 ACS Detailed Tables containing an open-ended distribution:

Table ID Low Value Jam Value Definition High Value Jam Value Definition
B01002 0 1- 116 115+
B01002A 0 1- 116 115+
B01002B 0 1- 116 115+
B01002C 0 1- 116 115+
B01002D 0 1- 116 115+
B01002E 0 1- 116 115+
B01002F 0 1- 116 115+
B01002G 0 1- 116 115+
B01002H 0 1- 116 115+
B01002I 0 1- 116 115+
B05004 0 1- 116 115+
B06002 0 1- 116 115+
B06002PR 0 1- 116 115+
B06011 2499 2,500- 100001 100,000+
B06011PR 2499 2,500- 100001 100,000+
B07002 0 1- 116 115+
B07002PR 0 1- 116 115+
B07011 2499 2,500- 100001 100,000+
B07011PR 2499 2,500- 100001 100,000+
B07402 0 1- 116 115+
B07402PR 0 1- 116 115+
B07411 2499 2,500- 100001 100,000+
B07411PR 2499 2,500- 100001 100,000+
B08103 0 1- 116 115+
B08121 2499 2,500- 100001 100,000+
B08503 0 1- 116 115+
B08521 2499 2,500- 100001 100,000+
B10010 2499 2,500- 200001 200,000+
B19013 2499 2,500- 200001 200,000+
B19013A 2499 2,500- 200001 200,000+
B19013B 2499 2,500- 200001 200,000+
B19013C 2499 2,500- 200001 200,000+
B19013D 2499 2,500- 200001 200,000+
B19013E 2499 2,500- 200001 200,000+
B19013F 2499 2,500- 200001 200,000+
B19013G 2499 2,500- 200001 200,000+
B19013H 2499 2,500- 200001 200,000+
B19013I 2499 2,500- 200001 200,000+
B19019 2499 2,500- 200001 200,000+
B19049 2499 2,500- 200001 200,000+
B19080 2499 2,500- 200000 200,000+
B19113 2499 2,500- 200001 200,000+
B19113A 2499 2,500- 200001 200,000+
B19113B 2499 2,500- 200001 200,000+
B19113C 2499 2,500- 200001 200,000+
B19113D 2499 2,500- 200001 200,000+
B19113E 2499 2,500- 200001 200,000+
B19113F 2499 2,500- 200001 200,000+
B19113G 2499 2,500- 200001 200,000+
B19113H 2499 2,500- 200001 200,000+
B19113I 2499 2,500- 200001 200,000+
B19119 2499 2,500- 200001 200,000+
B19121 2499 2,500- 200001 200,000+
B19125 2499 2,500- 200001 200,000+
B19126 2499 2,500- 200001 200,000+
B19202 2499 2,500- 200001 200,000+
B19202A 2499 2,500- 200001 200,000+
B19202B 2499 2,500- 200001 200,000+
B19202C 2499 2,500- 200001 200,000+
B19202D 2499 2,500- 200001 200,000+
B19202E 2499 2,500- 200001 200,000+
B19202F 2499 2,500- 200001 200,000+
B19202G 2499 2,500- 200001 200,000+
B19202H 2499 2,500- 200001 200,000+
B19202I 2499 2,500- 200001 200,000+
B19215 2499 2,500- 200001 200,000+
B19326 2499 2,500- 100001 100,000+
B20002 2499 2,500- 100001 100,000+
B20004 2499 2,500- 100001 100,000+
B20017 2499 2,500- 100001 100,000+
B20017A 2499 2,500- 100001 100,000+
B20017B 2499 2,500- 100001 100,000+
B20017C 2499 2,500- 100001 100,000+
B20017D 2499 2,500- 100001 100,000+
B20017E 2499 2,500- 100001 100,000+
B20017F 2499 2,500- 100001 100,000+
B20017G 2499 2,500- 100001 100,000+
B20017H 2499 2,500- 100001 100,000+
B20017I 2499 2,500- 100001 100,000+
B21004 2499 2,500- 100001 100,000+
B22008 2499 2,500- 200001 200,000+
B23013 0 1- 116 115+
B24011 2499 2,500- 100001 100,000+
B24012 2499 2,500- 100001 100,000+
B24021 2499 2,500- 100001 100,000+
B24022 2499 2,500- 100001 100,000+
B24031 2499 2,500- 100001 100,000+
B24032 2499 2,500- 100001 100,000+
B24041 2499 2,500- 100001 100,000+
B24042 2499 2,500- 100001 100,000+
B24081 2499 2,500- 100001 100,000+
B24082 2499 2,500- 100001 100,000+
B24091 2499 2,500- 100001 100,000+
B24092 2499 2,500- 100001 100,000+
B24121 2499 2,500- 100001 100,000+
B24122 2499 2,500- 100001 100,000+
B24123 2499 2,500- 100001 100,000+
B25018 14.1 14.0+    
B25021 14.1 14.0+    
B25035 1939 1939- 2005 2005
B25037 1939 1939- 2005 2005
B25039 1969 1969- 2005 2005
B25057 99 100- 3001 3,000+
B25058 99 100- 3001 3,000+
B25059 99 100- 3001 3,000+
B25064 99 100- 3001 3,000+
B25071 9.9 10.0- 90.1 90.0+
B25076 999 10,000- 1000001 1,000,000+
B25077 999 10,000- 1000001 1,000,000+
B25078 999 10,000- 1000001 1,000,000+
B25083 999 10,000- 1000001 1,000,000+
B25088 99 100- 6001 6,000+
B25088 2001 2,000+    
B25092 9.9 10.0- 50.1 50.0+
B25097 999 10,000- 1000001 1,000,000+
B25099 2499 2,500- 200001 200,000+
B25103 199 200- 10001 10,000+
B25105 99 100- 6001 6,000+
B25107 999 10,000- 1000001 1,000,000+
B25109 999 10,000- 1000001 1,000,000+
B25111 99 100- 3001 3,000+
B25113 99 100- 3001 3,000+
B25119 2499 2,500- 200001 200,000+


The following are the special data values (and their meaning), which can appear in the 2008 ACS Summary File table as an explanation for the absence of data:

Missing Value = ".": A dot ".", indicates that the estimate is unavailable. All ACS tables contain these values when estimates are missing due to certain special conditions.

Filtered Value or Geographic Restriction =" ": A blank indicates that a value is filtered or is not shown due to a geographic restriction.

Margin of Error (MOE) or Standard Error (SE) = 0: Estimate is controlled, which indicates the estimates are controlled and a statistical test is not appropriate.

2) Rounding Rules, Margin of Errors (MOE), and Standard Errors (SE)

A. B00001, B00002, B98001, and B98002 are sample counts, not estimates, and do not have MOEs and SEs associated with them. Tables in series B99* imputation tables and B98* quality measure tables (except B98001 and B98002) do not have MOEs calculated for them. The MOE and SE are set to -1 for these tables.

B. There are a few special rules on how certain margin of error and standard error are determined for ACS estimates. The accuracy of the estimate (decimal place) in the base tables to determine how many digits the standard error should be rounded. The only exceptions to these rules are tables

B19082: SHARES OF AGGREGATE HOUSEHOLD INCOME BY QUINTILE and B19083: GINI INDEX OF INCOME INEQUALITY. On American FactFinder (AFF), the estimates display to 2 decimal places and the MOE to 3.

3) Display of Estimates
Display of whole numbers in the summary files: The estimates in the summary files are stored using standard notation instead of in scientific notation. The largest estimate in the 2008 Summary File contains 14 digits, because since SAS was used to generate the 2008 Summary File, SAS automatically stores and displays values with more than 12 digits using scientific notation, but these values were stored in the summary files as whole numbers.

Display of decimal values in the summary files: The following median and ratio tables are displayed as decimals. The following list shows these tables, their table types, and accuracy.

Table ID Table Title Table Type Accuracy
B01002 MEDIAN AGE BY SEX MEDIAN Tenths
B01002A MEDIAN AGE BY SEX (WHITE ALONE) MEDIAN Tenths
B01002B MEDIAN AGE BY SEX (BLACK OR AFRICAN AMERICAN ALONE) MEDIAN Tenths
B01002C MEDIAN AGE BY SEX (AMERICAN INDIAN AND ALASKA NATIVE) MEDIAN Tenths
B01002D MEDIAN AGE BY SEX (ASIAN ALONE) MEDIAN Tenths
B01002E MEDIAN AGE BY SEX (NATIVE HAWAIIAN AND OTHER PACIFIC ISLANDER ALONE) MEDIAN Tenths
B01002F MEDIAN AGE BY SEX (SOME OTHER RACE ALONE) MEDIAN Tenths
B01002G MEDIAN AGE BY SEX (TWO OR MORE RACES) MEDIAN Tenths
B01002H MEDIAN AGE BY SEX (WHITE ALONE, NOT HISPANIC OR LATINO) MEDIAN Tenths
B01002I MEDIAN AGE BY SEX (HISPANIC OR LATINO) MEDIAN Tenths
B05004 MEDIAN AGE BY CITIZENSHIP STATUS BY SEX MEDIAN Tenths
B06002 MEDIAN AGE BY PLACE OF BIRTH IN THE UNITED STATES MEDIAN Tenths
B06002PR MEDIAN AGE BY PLACE OF BIRTH IN PUERTO RICO MEDIAN Tenths
B07002 MEDIAN AGE BY RESIDENCE 1 YEAR AGO IN THE UNITED STATES MEDIAN Tenths
B07002PR MEDIAN AGE BY RESIDENCE 1 YEAR AGO IN PUERTO RICO MEDIAN Tenths
B08103 MEDIAN AGE BY MEANS OF TRANSPORTATION TO WORK MEDIAN Tenths
B08503 MEDIAN AGE BY MEANS OF TRANSPORTATION TO WORK FOR WORKPLACE GEOGRAPHY MEDIAN Tenths
B12008 MEDIAN AGE AT FIRST MARRIAGE MEDIAN Tenths
B12008A MEDIAN AGE AT FIRST MARRIAGE (WHITE ALONE) MEDIAN Tenths
B12008B MEDIAN AGE AT FIRST MARRIAGE (BLACK OR AFRICAN AMERICAN ALONE) MEDIAN Tenths
B12008C MEDIAN AGE AT FIRST MARRIAGE (AMERICAN INDIAN AND ALASKA NATIVE ALONE) MEDIAN Tenths
B12008D MEDIAN AGE AT FIRST MARRIAGE (ASIAN ALONE) MEDIAN Tenths
B12008E MEDIAN AGE AT FIRST MARRIAGE (NATIVE HAWAIIAN AND OTHER PACIFIC ISLANDER ALONE) MEDIAN Tenths
B12008F MEDIAN AGE AT FIRST MARRIAGE (SOME OTHER RACE ALONE) MEDIAN Tenths
B12008G MEDIAN AGE AT FIRST MARRIAGE (TWO OR MORE RACES) MEDIAN Tenths
B12008H MEDIAN AGE AT FIRST MARRIAGE (WHITE ALONE, NOT HISPANIC OR LATINO) MEDIAN Tenths
B12008I MEDIAN AGE AT FIRST MARRIAGE (HISPANIC OR LATINO) MEDIAN Tenths
B19082 SHARES OF AGGREGATE HOUSEHOLD INCOME BY QUINTILE GINI Tenths
B19083 GINI INDEX OF INCOME INEQUALITY GINI Thousandths
B23013 MEDIAN AGE BY SEX FOR WORKERS 16 TO 64 YEARS MEDIAN Tenths
B23020 MEAN USUAL HOURS WORKED IN THE PAST 12 MONTHS FOR WORKERS 16 TO 64 YEARS RATIO Tenths
B23021 MEAN WEEKS WORKED IN THE PAST 12 MONTHS FOR WORKERS 16 TO 64 YEARS RATIO Tenths
B25010 AVERAGE HOUSEHOLD SIZE OF OCCUPIED HOUSING UNITS BY TENURE RATIO Hundredths
B25018 MEDIAN NUMBER OF ROOMS MEDIAN Tenths
B25021 MEDIAN NUMBER OF ROOMS BY TENURE MEDIAN Tenths
B25071 MEDIAN GROSS RENT AS A PERCENTAGE OF HOUSEHOLD INCOME IN THE PAST 12 MONTHS (DOLLARS) MEDIAN Tenths
B25092 MEDIAN SELECTED MONTHLY OWNER COSTS AS A PERCENTAGE OF HOUSEHOLD INCOME IN THE PAST 12 MONTHS MEDIAN Tenths


4) Special Table ID Sequence Rules
The data from the American Community Survey contains 75 detailed tables that have different table layouts for the Puerto Rico than their United States counterparts. The United States version of the tables are limited to geographic areas in the US (50 states plus the District of Columbia) while the Puerto Rico versions are limited to areas in Puerto Rico. In the summary file the Puerto Rico version of the tables are in sequence file 149 through 158. Therefore, for all geographic areas within the US sequence files 149 through 158 will be blank. In addition, sequence files 1,2,23,24, 28-32, and 147 will be blank for Puerto Rico as they contain the US version of the tables. The decision to separate the files was made because the comparable tables between the US and Puerto Rico may have a different number of cells (such as C06001 with 45 cells and C06001PR with 37 cells) which would significantly alter the metadata between the US and Puerto Rico. To identify what tables are available for Puerto Rico only look for the "PR" suffix in the table id (e.g. C06001PR).

For more information on PR only sequences that are counterparts to states-only sequences, please reference the following table.

US/State-only Sequences PR Only Sequences
1 (US) 149 (PR)
2 (US) 150 (PR)
23 (US) 151 (PR)
24 (US) 152 (PR)
28 (US) 153 (PR)
29 (US) 154 (PR)
30 (US) 155 (PR)
31 (US) 156 (PR)
32 (US) 157 (PR)
147 (US) 158 (PR


Sequences 51 and 146 contain many geo-restricted tables. Sequences 125-133 contain 3 large median tables with 499 cells. Due to the size restriction on the sequences (no more than 245 cells), each of the tables had to be broken into 3 sequences. So for example, sequence 125 contains B24121 cells 1-167, sequence 126 contains B24121 cells 168-333; sequence 127 contains B24121 cells 334-499, etc.

5) ACS User Notes
ACS User Notes are available on:
http://www.census.gov/acs/www/UseData/usernotes.html

6) Detailed Table Geographic Restrictions
ACS 2008 base tables that were subject to geographic restrictions are located on:
http://www.census.gov/acs/www/Products/users_guide/ACS2008_Data_Product_Geographic_Restriction.xls

7) Data Release Filtering Rules
Data release filtering rules. Filtering rules, based on the statistical reliability of the survey estimates, are used because certain geographic areas contain very detailed tables might include estimates whose reliability is unacceptable. The main data release rule for the ACS tables works as follows. 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 can be 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.

For a complete list of filtered detailed tables, please reference the filter_helper_file.txt located on http://www2.census.gov/acs2008_3yr/summaryfile/

8) 2008 1-Year Detailed Tables that are not available for the 2008 3-Year data release
Selected detailed tables that were published for the 2008 1-Year data release are not available for the 2008 3-Year data release. For a complete list of these tables, please reference the following file:
http://www2.census.gov/acs2008_3yr/summaryfile/
Tables_in_1Year_NOT_in_3year.xls. For more information on changes to the detailed tables please reference the 2008 Data Product Changes page on the ACS Website on:
http://www.census.gov/acs/www/Products/2008/new_notable_dp_changes.html