Strategic voting in Epsom

Recall that if Rodney Hide keeps his district seat in Epsom, New Zealand's MMP rules mean that ACT is awarded seats proportionate to its share of the party vote even if its share of the party vote is below the five percent threshold.

Matthew Hooton Saturday predicted that Key would use current high poll ratings to finish off ACT, which he reckons would be a mercy killing.

Monday, Rob Hosking reported instead:

National’s message to its Epsom supporters looks likely to boil down to: “take a long anaesthetic swig of single malt, go down to the polling booth and vote for Hide.”

The iPredict contract on ACT electing at least one member dropped a bit with Hooton's column then came back up with Hosking's. The contract on Hide's winning Epsom didn't move with Hooton's column, but moved a bit subsequent to Key's comments reported by Hosking. The market had already priced in Hooton's analysis but moved in response to Key's statements. There's currently about a 64% chance that ACT returns to Parliament, deriving entirely from Hide's chances of winning Epsom.

Farrar notes some of the strategic voting implications for Epsom. I'll add a few more.

• If you believe that ACT is an effective party on the right:
  • Labour and Green should want to kill off ACT and choose National for their electorate vote.
  • National supporters should vote for ACT.
• If you believe that ACT is ineffective and, in the absence of ACT, either economic liberals will move back to National and move National's preferred policy position or form a new and more effective liberal party:
  • Labour and Green voters should vote for Rodney Hide in Epsom.
  • Centrist National voters who genuinely like Key's current policies should vote for Hide in Epsom
  • Bluer National voters should vote for National in Epsom.

It will be awfully interesting to have a look at the details of split ticket voting in Epsom after the election.