Quote Originally Posted by renf View Post
The Census Bureau estimates were reasonably accurate for 2001 through 2008. The 2009 estimate was way off. Detroit advocates asked the Census Bureau to redo the procedures they used for the 2009 estimate and the Census Bureau did so. Thus the 2009 estimate was way too large. After that the Census Bureau reverted to using their former procedures.
There will, undoubtedly, be some surprises in the 2020 census counts.
It wasn't only Detroit that got a revised estimate for 2009. Chicago and Cleveland also got their estimates revised up, quite substantially, between 2008 and 2009. The 2008 estimates for those two cities were actually extremely accurate according to the 2010 census, while the 2009 estimate was wildly overstated. On the other hand, even Detroit's 2008 estimate was significantly overstated, since it was off by nearly 100,000 from the actual 2010 population.