I’ve been trying to find a way to combine both geographic and proportional representation. First, consider allowing MPs to vote with varying strengths (e.g. if an MP represents 45k people, they vote in parliament with a strength of 45k). The only trouble with this approach is that it isn’t proportional to the popular vote.
Instead, consider something akin to a federal MMP. If your chosen candidate doesn’t win, your vote is transferred to the party leader of your choice: a two-part ballot. In our current system, you aren’t represented unless you voted for the winning candidate of your riding.
To estimate the outcome of this new system, let’s assume that vast majority voting for a candidate support their party too. Each geographic seat would be the same as it is now. For example, Vancouver Centre’s Hedy Fry still represents the riding, but only at a power of 18k. The remaining 41k ballots are transferred to the appropriate parties.
Nationally, 2.17m ballots would be transferred to the Liberals from voters in ridings where they didn’t win, 2.13m to the NDP, 1.44m to the Conservatives, 818k to the Bloc, and 539k to the Green Party. The end result has the geographic representatives holding 7.42m geographically proportional votes and the party representatives holding 7.10m, resulting in a party proportional parliament.
Gerrymandering in this system would be moot, although I gather voting fraud might rise. There’s also the question of who would hold the party seats. The party leaders seems like the most direct answer, but I’m not sure how I feel about any one representative wielding upwards to 15% of the total voting power in parliament.