I’ve been trying to work with some of the ACS data for counties in Illinois. I am specifically interested in PUMA 1600, although I’ve seen similar issues and am concerned about these other PUMAs in the state. Based on the ACS 5 yr. data for 2008-2012 that I downloaded, there are approximately 29,000 people in the 5 counties that make up PUMA 1602 (Code 17 01602). Based on what these coutnties individual populations sumed together, there should be approximately 148,000. It was my understanding that PUMAs had to be made up of 100,000 people or more to keep the data from being identifying so I am a bit confused as to what these PUMAS of <100,000 really represent. Any help would be greatly appreciated in understanding:
Why this might be the case?
What might be a way to work around it?
Or if I need to use a different data set what recommendations there might be for an alternative set?
We need to be able to break them down into PUMAs for the demographic information we are trying to retreive. Because of this, the 5-year was our best bet. Any help would be greatly appreciated. Thank you.