Couldn't you just do the exact same thing with "valid votes" and say the same thing that the parent has said?
[0] - http://www.techly.com.au/2016/06/30/australia-votes-whats-do...
Yes, donkey voting is a problem as well. But there's a stigma around it as well (as that article shows). Invalid voting on the other hand doesn't have a stigma around it.
> Couldn't you just do the exact same thing with "valid votes" and say the same thing that the parent has said?
Maybe. But if someone makes the decision to tick random boxes rather than write "fuck you" then it's clear that they've made a decision to make a vote. It's a grey area, and I despise the issue of donkey voting, but you can't deny that the person has "had their say".
However, the number of invalid votes is counted though. And even considering invalid votes, the percentage of valid votes is better than most countries which don't have mandatory voting. Not to mention that invalid voting is known to be a method of abstaining from voting. I don't know what the stats are for donkey voting, but I doubt that a large enough portion of people do it for it to classify as that large of an issue.
We have many different ways of voting, so it's designed to be as easy as possible for people to vote (in contrast to what I've heard from Americans). The fines are not that bad for first-time offenders but they're large enough that it discourages people from not voting (the fine gets larger for subsequent offenders).
The rules for voting in elections and referendums are also the same (so the same fines apply).
Not in Australia. Here we have compulsory voting, and referendums have to have a double majority in order to pass (so there's no question about whether the majority of the people actually wanted the change).
So multiplying by voter turnout would not meaningfully change the results (voter turnout is >95%). Maybe more countries should adopt mandatory voting...