Picking parliament proportions precisely

Every election, I wonder how voting could be improved to ensure the parliament we get is a true representation of what we want. One idea I (and many others, I’m sure) have had is to vote on policies, not parties. That would mean doing something like the Vote Compass and then your vote going to the party that most closely aligns with your points of view. There are a number of downsides to that, but one of the biggest is that it is too much effort for a lot of people, and would probably just put people off of voting altogether.

Another idea I had prior to this past election was for voters to vote on the makeup of parliament itself, not just the number one party they wanted in. That means they could give 60% of their vote to Labour, 30% to Greens and maybe 10% to National because they agree with them just a little bit. The obvious issue with that system is the same as the system above, in that it is too much effort for a lot of people. Then I thought of a simplified system that would rely heavily on computer vision, but is nothing current technology can’t handle.

Normalised proportional voting (NPV; because every voting system needs an acronym) would mean people could put as much or as little effort into voting as they’d like. Voters would have a very similar ballot paper to what we have now, but they could put as many ticks against a party as they liked. The ballot paper would then be scanned and the proportion of ticks against each party calculated and normalised to 1. This means each voter still gets one vote, but it is split between parties to represent how they’d like to see parliament. So, for example, 4 ticks for Labour, 2 for Greens and 1 for National would split the vote 0.6 to Labour, 0.3 to Greens and 0.1 to National (rounded to one decimal place, but it wouldn’t need to be). It wouldn't matter how many ticks you gave overall, as it would all get normalised to 1. And if you can’t be bothered with all that ticking, you can just give one tick to your favourite party and they get the whole vote. It doesn’t have to be ticks either, that’s just how the current system works.

The closest voting system I’ve found (and I’ve never studied politics, so I’m relying on Wikipedia here) is Single Transferable Vote (STV). However, that would require voters to rank parties, and the preference between 1st and 2nd is not always the same as between 2nd and 3rd. The NPV system would more accurately reflect the voter party preferences.

As I said, I’m not a politics major or anything, so there are probably huge holes in this system. But I feel like it might have legs in some form or another, and I’d love to hear from those of you more knowledgeable than me as to why it would or would not be a good idea.

To get the ball rolling, here are some thoughts I had on why it may or may not work or be adopted:

1. The computer processing may be untrustworthy, or be viewed as untrustworthy.
2. Splitting your vote may be seen as diluting it, so people would just revert to giving a single vote out of fear of their 'number 1' party not gaining power.
3. Smaller parties might have more of a shot of getting into parliament, as people could throw them a bone if they kind of want them to be there, but not enough to waste a whole vote.
4. There is huge potential for analysis into how people view parties in relation to each other, e.g. 67% of people who gave National 0.6 or above also gave Greens at least 0.1.
5. Smaller parties may form to fill a niche made apparent by the analysis of voting patterns, e.g. if 67% of people who gave National 0.6 or above also gave Greens at least 0.1, then maybe there is room for a Blue-Green party.