| Documentation: | Citizen Voting Age Population Special Tabulation (ACS 2009-5 Year Estimates) |
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Publisher: U.S. Census Bureau
| Document: | Citizen Voting Age Population (CVAP) Special Tabulation |
| citation: | Social Explorer; U.S. Census Bureau; Citizen Voting Age Population (CVAP) Special Tabulation From the 2005-2009 5-Year American Community Survey (ACS) |
- The estimates from the ACS are based on a sample survey and hence are subject to sampling error. An approximate 90 percent confidence interval for each estimated count is given by the (CVAP_LO, CVAP_HIGH, where CVAP_LO = MAX(0, CVAP_EST - CVAP_MOE) and CVAP_HI = CVAP_EST + CVAP_MOE, and CVAP_MOE is the margin of error provided in the CVAP table. Note that to avoid negative counts, which are logically impossible, the lower limit, CVAP_LO is set to zero when the CVAP_MOE is greater than CVAP_EST, as can happen in areas where the ACS sample is small. {In fact we know the lower limit is bounded below by the number of cases in the ACS sample, but this detail is ignored to keep tables concise.} The interval based on the margin of error is an approximate 90 percent confidence interval, and its coverage of the true value can deviate from the nominal level of 90 percent, particularly when the ACS sample size is small. Nevertheless, it gives an indication of the sampling error associated with the estimate.
- Because this is a special tabulation of data and not part of the standard data products shown on the Bureau's American Factfinder web site, these estimates are rounded. Therefore, the detail may not exactly add to the total. For example, the sum of each of the race groups for non-Hispanics may not be the same as the estimate given for non- Hispanics.
- These estimates will not match counts from the 2010 Census. The ACS data were collected for and represent the five-year period from 2005 to 2009, and the Census data represent April 1, 2010. Totals in the ACS were adjusted based on data from the Bureau's Population Estimates program, which was based on Census 2000 adjusted for population changes through the decade. The political geography for the ACS data in this tabulation is based on borders as of January 1, 2009, and the Census is based on boundaries as of January 1, 2010. The tracts and block groups are from Census 2000, except for 26 counties (see the footnote on page 1), and the 2010 Census data uses 2010 Census tracts and block groups.
- There are cases where the MOE is missing (a "." in SAS or blank in the CSV files). Those are situation where the estimate is controlled to the Population Estimates and therefore there is no margin of error.
