ACS Data Users Group

Hi,

This is a pretty basic question but I can't seem to find a concise explanation online, and I'm pretty new to the ACS! I'm just looking up general data on the racial/ethnic make-up of Illinois and Illinois counties in 2016 (using 2012-2016 ACS 5-Year Estimates). For those who identify as Hispanic or Latino, many of the counties are missing MOE data and instead have five asterisks (*****). The explanation the ACS provides is: "An '*****' entry in the margin of error column indicates that the estimate is controlled. A statistical test for sampling variability is not appropriate." Does this mean that the estimates the ACS provides in these cases are not valid/reliable? I'd like to calculate a coefficient of variation for these estimates but I can't do it without a margin of error. Any help would be greatly appreciated!

Hi Bill,
The asterisks mean that this particular ACS estimate has been controlled to the Census Bureau's official population estimate for this racial/ethnic group. So there is no sampling error associated with the estimate. The Census Bureau's "Accuracy of the Data" document states the following:

"If the margin of error is displayed as ‘*****’ (five asterisks), the estimate has been controlled to be equal to a fixed value and so it has no sampling error. A standard error of zero should be used for these controlled estimates when completing calculations, such as those in the following section."

See: www2.census.gov/.../MultiyearACSAccuracyofData2016.pdf (Page 11)

I hope this helps,
-Mark

Thank you, Mark! This is extremely helpful.