The AHS is a Housing Unit Survey
The AHS is a longitudinal housing unit survey that asks questions about the quality of housing in the United States. Returning to the same housing units every other year to gather data, this survey allows users the unique opportunity to analyze housing and household changes over long periods of time. In gathering information, Census Bureau interviewers visit or telephone the household occupying each housing unit in the sample. For unoccupied units, they obtain information from landlords, rental agents, or neighbors. The survey is redesigned from time to time to make sure it meets current needs and new topics are introduced for specific survey years.
In the past, the AHS was two surveys conducted independently of one another. The National survey was enumerated every other odd-numbered year, while the Metropolitan survey occurred in selected areas on a rotating basis. Starting in 2007, the National and Metropolitan surveys were conducted in the same time-period to reduce costs. Although they were collected simultaneously, the resulting data were not pooled to produce a single set of estimates. The national cases were used for regional- and national-level estimates, while the metropolitan cases were used for specific-area estimates.
In 2009, a supplemental sample of housing units in Chicago, Detroit, New York, Northern New Jersey, and Philadelphia were combined with the existing National sample in these areas to produce metropolitan level estimates. Only Seattle and New Orleans were stand-alone Metropolitan surveys.
In 2011, there was no AHS-Metropolitan Sample. Instead, a supplemental sample of housing units was drawn for selected metropolitan areas. This supplemental sample was combined with the National Sample in these areas in order to produce metropolitan estimates using the National survey.
In 2013, survey design reverted back to the 2009 method, where a supplemental sample of housing units in Chicago, Detroit, New York, Northern New Jersey, and Philadelphia were combined with the existing National sample in these areas to produce metropolitan level estimates. In addition to these 5 areas, the 2013 supplemental sample also included 20 other metro areas, bringing the total number sampled to 25 metropolitan areas. These additional 20 metro areas were stand-alone Metropolitan surveys. In 2013, five rotating topical modules were included in the survey. To alleviate respondent burden, the AHS used a split-sample approach for four of the new modules. The entire sample was randomly split in half. The first half of the sample was asked questions from the Disaster Planning and Public Transportation topical modules. The second half was asked questions from the Neighborhood Observation and Collective Efficacy topical modules. Both the 2011 and 2013 samples included an oversample of assisted housing units drawn from HUD administrative records. For more on 2013 weighting, see Sample Selection and Size section below.
For an explanation of the nuances of geography concerning the 2011 American Housing Survey, see 2011 American Housing Survey Geography Overview [PDF - 617 KB].
Sample Selection and Size
Housing units participating in the AHS have been scientifically selected to represent a cross section of all housing in the nation. The same basic sample of housing units is interviewed every two years until a new sample is selected. The U.S. Census Bureau updates the sample by adding newly constructed housing units and units discovered through coverage improvement efforts.
Each housing unit in the AHS national sample is weighted and represents about 2,000 housing units in the United States. The weighting is designed to minimize sampling error and utilize independent estimates of occupied and vacant housing units. Information regarding the sample size and response rate can be found in National Report Appendix B. For metro survey methodology, see Metropolitan Report Appendix B. See Technical Documentation for Appendices.
Due to the pooling of the national sample and 5 metropolitan samples, the 2013 sample includes approximately 84,400 housing units. Unlike 2011, there is a separate metropolitan area sample in 2013 and the sample still includes additional subsidized housing units selected from a sample of HUD administrative records. As a result of the split-sample approach described in the Survey Design section above, three separate weights were developed for the 2013 AHS:
- One weight is applicable to all characteristics except those pertaining to the four split sample topical modules mentioned above,
- A second weight is applicable to the Disaster Planning and Public Transportation topical modules,
- A third weight is applicable to Neighborhood Observation and Collective Efficacy topical modules.
The data in this report are subject to error from sampling and other causes, such as incomplete data and wrong answers. Appendix D contains a complete description of the types of errors and provides formulas for constructing confidence intervals. See Technical Documentation for Appendices.