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 following file:
http://www2.census.gov/acs2008_1yr/filter_helper_file.txt
