Gary Barnes, a professor at the University of Minnesota, wrote a paper back in 2001 that calculated weighted densities for a number of U.S. urbanized areas. Like me, he used the term "perceived density."
He used traffic zones rather than census tracts as his base unit. Traffic zones generally are smaller than census tracts, which causes his weighted densities to be somewhat higher than mine for some cities. (Weighted density rises as the geographical area is cut up into smaller units.)
I wasn't aware of this paper when I wrote my posts. If I had been, I wouldn't have spent all that time largely duplicating his work. But I do want to give the man credit. (And I suspect that since he is a professor paid to do this kind of thing and I'm just a lawyer screwing around in his spare time, his work is more thorough.)
Thanks to the Overhead Wire and that other a.c. for the pointer.