Benjamin Clayborne
Auror
From the first book, at least, we don't know the populations of the other districts. It wouldn't be implausible for D12 to have a pop of 8,000 and for (some of? most of?) the other districts to have populations five or ten times that size. (California's population is 66 times Wyoming's, for example.) There's no reason why D12 has to be comparable in size to the other districts.
That said, it's possible that books 2/3 reveal details about the populations of the rest of Panem; I haven't read them yet.
That said, it's possible that books 2/3 reveal details about the populations of the rest of Panem; I haven't read them yet.