RE: [CTPP] ACS 2005-2007 Population Estimates

I appreciate everyone's responses. I'm also curious if anyone knows what 3- and 5-year ACS data sets will benefit from Census 2010 population counts. Will the 2008-2010 3-year and 2006-2010 5-year (both released in fall 2011) be the first small area data sets to use the 2010 decennial census to develop period estimates? --------------------------------------------------------------- Shimon Israel Associate Transportation Planner/Analyst Metropolitan Transportation Commission 101 Eighth Street Oakland, CA 94607-4700 (510) 817-5839 (office) (510) 817-5848 (fax) --------------------------------------------------------------- Shimon: I just wanted to add my comments about ACS and population figures, based on my own experience in the Little Rock region and my agency, Metroplan (the MPO for this region). 1. I have found similar disagreement between my population/housing estimates and the ACS. The census estimates upon which ACS is based have tended to under-count population in past decades, so it's not unreasonable to assume they're doing the same now. 2. Due to a quirk in state law, Arkansas has a number of mid-decade special censuses in fast-growing cities. In 2005-2007 we went through a cycle of these in which, as usual, Metroplan's population estimates came very close to the special census figures, while the census estimates were often low. 3. A firm in our region, the Gadberry Group, has developed its own system of estimating population based on consumer data. While this runs into that scary "death of privacy" issue, these guys use the things the corporate world knows about us to estimate population, household income, ethnicity etc. to sell as marketing information to large retailers and other firms. Anyway, the Gadberry Group's population estimates for our region have come in considerably higher than our own estimates, and hence that much higher than the generally low census estimates. I don't know what this means. I think Gadberry estimates are a bit too high, but this may be further verification that census estimates run low. 4. While they would not release specific information, Gadberry endorsed my view, supported by recent ACS results, that household size has risen and occupancy has dropped recently in local communities in response to the housing and economic crisis. While there has been a lot of criticism of ACS, my intuition is that it's on the right track and the qualitative information it provides fits with hints from other data sources. That said, I think we all need to be looking at ACS results with circumspection; it's only been around a few years. There are always surprises when the census figures finally come out. I'm sure Census 2010 will be no exception. Jonathan Lupton Research Planner Metroplan 501-372-3300 _______________________________________________ ctpp-news mailing list ctpp-news(a)chrispy.net http://www.chrispy.net/mailman/listinfo/ctpp-news