New article on Guardian CIF's election blog up today. (series here)
Initially, our prediction model included a small but seemingly robust incumbency factor, a decision that was certainly influenced by our US election experience. We have since taken it out, determining that the incumbents effect is quite difficult to generalize across the 2010 electoral playing field, and probably will be quite different than what was observed in the 2005 data from which the factor was drawn.
Renard Sexton is FiveThirtyEight's international affairs columnist and is based in Geneva, Switzerland. He can be contacted at firstname.lastname@example.org