I would like to make two corrections to my post on Rein Taagepera’s study of the size of empires.
When I compared the 2006 and 2009 updates to Taagepera’s lists, I missed one new empire in the 2009 article: Scythia. I have added it to the original post.
I said that the 2006 article added eight empires to Taagepera’s lists. I was wrong. I trusted a note on page 221 of the 2006 article by Turchin, Adams, and Hall:
Our list of large historical states was based on the compilation by Taagepera, which has been systematized and posted on the web by Chase-Dunn and coworkers http://irows.ucr.edu/. We checked the Taagepera list with all major historical atlases in the library of the University of Connecticut and found eight additional empires that fit our criteria (Axum, Hsi-Hsia, Kara-Khitai, Srivijaya, Maurian, Kushan, Gupta, and Maratha).
Four of their eight empires (Axum/Aksum in the Horn of Africa, Srivijaya in Indonesia, the Hsi-Hsia/Western Xia who were rivals of the Song Dynasty in China, and Maratha in South Asia) appear to be absent from Taagepera’s articles, but the other four are present and accounted for: Kara-Khitai (as W. Liao in Taagepera 1997), Gupta (Taagepera 1979 p. 132), Kushan (Taagepera 1979 p. 132), Maurian (as Maurya in Taagepera 1979 p. 132).