3 février 2022
United States. Bureau of the Census, « (Restricted) American Community Survey Unedited Microdata », Inter-university Consortium for Political and Social Research, ID : 10.3886/ICPSR37803.v1
The American Community Survey (ACS) is part of the Decennial Census Program. This survey is sent to a random sample of households in the United States and Puerto Rico on a rotating basis. The ACS collects information from U.S. households similar to what was collected on the decennial census "long form," such as age, race, sex, Hispanic origin, income and benefits, health insurance, education, veteran status, disabilities, place of work and commuting, and housing costs. These data previously were collected only in census years in conjunction with the decennial census. Since the ACS is conducted every year, rather than once every ten years, it provides more current data throughout the decade. The ACS Unedited Microdata file is a swapped file that contains some unedited variables. The ACS is an ongoing survey that provides data on an annual basis. The ACS is a national survey sent to about 250,000 households each month or about 3,000,000 households per year. The ACS began in 1996, collecting data in a limited number of areas. The survey expanded in subsequent years, reaching full national coverage in 2005. The Census Bureau now conducts the ACS in every county of the United States. Beginning in 2009 the ACS also combines data collected over the preceding five years to provide aggregate data to the public for small areas with accuracy similar to the decennial census. The restricted access microdata files have also been combined in multi-year files, with a few modifications to the data to produce a unified file: First, the weights have been recalculated so that they roll up to the national total in the most recent year in the dataset. Second, all geography has been reconciled to be consistent with the most recent year. Third, dollar values have been adjusted for inflation. Fourth, in those cases where a question has changed, the multi-year data reflects a "lowest common denominator" version of that variable, so, for example, if valid responses to a survey question were changed from continuous to categorical, the continuous responses from earlier years would be changed to valid categorical values. Fifth, only those questions asked in all years will be included in the multi-year data files. That is, if a question is added to the survey or dropped from the survey during the five-year period, that variable will not be included in the five-year data file. Note: the ACS no longer combines data collected over three-year periods to provide aggregate data to the public for all areas of 20,000 or more.