² In 1993, the LDP “won” the election, in the sense that it won by far the most seats of any party and returned almost all incumbents—even if it did not go on to form a government because almost all the opposition parties unprecedentedly united in an unwieldy coalition that soon splintered.

³ See Pempel, T. J., ed., Uncommon Democracies: The One Party Dominant Regimes (Ithaca, N.Y.: Cornell University Press, 1990)Google Scholar.

⁴ See Scheiner, Ethan, Democracy without Competition in Japan: Opposition Failure in a One-Party Dominant State (New York: Cambridge University Press, 2006)Google Scholar.

⁵ Our forthcoming book advances novel arguments about the origin and development of kôenkai, PARC, and factions. Drawing on insights from historical institutionalism, we demonstrate the centrality of sequence, complementary institutions, and negative externalities to these institutions.

⁶ We thank Ethan Scheiner for providing this data and analysis.

⁷ This is because of “negative externalities,” meaning that a Diet member loses out by not joining a faction—and loses out incrementally more when more of his or her colleagues are in a faction. For a fuller discussion, see Krauss and Pekkanen, forthcoming; see also Krauss, Ellis S. and Pekkanen, Robert, “Explaining Party Adaptation to Electoral Reform: The Discreet Charm of the LDP?” Journal of Japanese Studies 30, no. 1 (Winter 2004): 1–34CrossRefGoogle Scholar.