Last weekend there were upsets in pre-selection battles over the two lower house seats of the Australian Capital Territory. The three largest local factions in the ALP did a preference deal with one another which was expected to deliver the right’s preferred candidate in the seat of Canberra (using the left’s preferences) and the left’s preferred candidate in the seat of Fraser (with the right’s preferences). It didn’t work out that way. Because the factions were unable to control the majority of their members both seats fell to independents. This sort of thing is uncommon but it shouldn’t be at all surprising.
The factions typically keep their members in line by threatening them with expulsion for two years if they vote against the group’s instructions. In this preselection vote the power-brokers insisted on seeing their member’s ballots to confirm they were obeying orders. For everyday decisions this sort of checking with the threat of punishment is sufficient to keep everyone in line. It’s not worth being thrown out of an influential group to alter a trivial decision. But as every student of game theory knows, there are two situations in which cooperation in a repeated game is especially difficult to maintain: final rounds and very important rounds. In the final round of a series of games there is little reason to cooperate because there will be no more opportunities for cooperation and the other side has no opportunity to punish you for defecting. Similarly, if one round is much more important than all the others the temptation to defect (act selfishly) is large, because the costs of punishment or non-cooperation in future rounds is small by comparison to the gains possible from defection in this round.
Decisions about preselection are far and away the most important ones made by party members and they occur very infrequently. Unsurprisingly then, for most faction members the threat of expulsion from the faction for two years was insufficient to deter them from voting for the candidate they preferred rather than the one their faction told them to. No decisions of comparable importance would be made in the next two years anyway. They may have also anticipated others doing the same calculation and realised the faction would be unwilling to expel half of their members for defecting. The trade-off was only in favour of unconditional cooperation for the careerists who benefit a great deal from showing absolute loyalty to their political tribe.
Given that ALP factions in lower house seats are primarily set up to influence these preselection battles, it’s somewhat ironic that they are precisely the decisions they have the most trouble controlling. They could perhaps keep their members in line with a stronger punishment (a longer period of expulsion, expulsion from a whole social group, surrender of a bond, etc) but then it’s not clear why anyone except the careerists would want to join in the first place. Really the factions are much less influential than their member numbers alone would make them seem.
In unrelated news, congratulations to blogger and social scientist Andrew Leigh for winning preselection in the ACT seat of Fraser. I hope you are as productive a politician as you were an academic!
Tagged: Australia, game theory, politics
