Updated January 12, 2012.

The 2010 Census and the American Community Survey (ACS) both measure vacancy. Because they differ in their design and data collection methods, users should note that the results may also differ. For example, the 2010 Census shows a gross vacancy rate of 11.4 percent while the 2010 ACS 1-year estimates show a rate of 13.1 percent. Historically we have noted similar differences between census and survey results regarding vacancy rates.

As examples of how the 2010 Census and the ACS differ, the 2010 Census measured vacancy as of April 1, 2010, while the 2010 ACS 1-year estimates measured vacancy throughout all of 2010 as of the date of interview. In addition, the ACS by necessity, had to draw a sample from our master address list before the 2010 Census operations had finished updating the address list. Thus, the 2010 ACS 1-year estimates do not measure the same universe of addresses as the 2010 Census. Also, the 2010 Census and the ACS differ in some of their data collection operations.

The 2010 Census results are useful for looking at small areas of geography while the 2010 ACS 1-year estimates are useful for looking at cross-tabulations of characteristics. For more information, read the report Comparing 2010 American Community Survey 1-Year Estimates of Occupancy Status, Vacancy Status, and Household Size with the 2010 Census - Preliminary Results.