I’m surprised that this hasn’t cropped up yet but no one seems to have measured voting power in the potential hung parliament. Tim Harford offers a nice primer for those unfamiliar with the idea. The way to think about it is, what value do individual independents have to form coalitions and win majority votes?
The Shapley-Shubik index seems to me to be appropriate for our current situation. Here are some scenarios. The last one is where the Nationals candidate wins O’Connor but decides to go independent. Notice that Tony Crook is far more valuable to the Coalition than he would be as an independent so you can see what will likely happen there.
Anyhow, this exercise demonstrates that the power of the independents changes little as there are more or less than them but who actually wins more seats amongst the majors matters alot. Specifically, if the major parties can sign on independents as ministers and lock them into their voting block that matters a great deal compared to an informal undertaking.
You can calculate these yourself on Dennis Leech’s website.