Mixed-Member Proportional Representation Explained


Queen Lion of the animal kingdom is looking to improve her democracy. She recently allowed citizens to elect representatives to the Jungle Council which governs the kingdom.

However, she recognizes that her citizens are not happy with the voting system. Let’s watch an election on one of the small islands of her Kingdom to see why:

On this island there are three political parties: the two big ones: Kea and Tuatara, and a small third party, Kakapo.

On election day, the citizens each cast one vote for a local candidate they want to represent the range they live in. The results are as follows:

With the average across the island that Tuatara gets 49%, Kea gets 48% and Kakapo gets 3%.

The election is run using First Past the Post, meaning that candidate with the most votes wins. Because Tuatara got the most votes in each range, they get to control 100% of the seats on the council.

And this is why so many citizens are unhappy. The majority of them, the 51% who voted for other parties, get no representation on the council at all.

This seems unfair to Queen Lion but she’s not sure how to fix it. The citizens like having local representatives and don’t want to change the range boundaries.

But luckily Kiwi, one of the citizens of this island, has a suggestion for Queen Lion on how she can make the system better while keeping local representation and leaving the ranges as they are.

The idea is called Mixed Member Proportional or MMP and it makes two changes: the number of seats on the council is doubled and each citizen gets two votes, not one.

Here’s how it works:

At first, election day for Kiwi is just the same as before.

He gets a list of candidates running to represent his local range on the council. Kiwi picks one and the winner will be the candidate with the most votes.

So far the system is no better – Tuatara again wins all the local elections and still more than half of the citizens don’t have any representation. But here’s how Kiwi’s second vote – and those extra seats on the council – fix this.

Kiwi uses his second vote to pick his favorite political party.

These second votes are tallied up and show the percentage of support that each of the political parties has among the citizens as a whole and reveals how imbalanced the council is so far.

To fix this imbalance, members of the political parties are added, one at a time, to make the council more proportional.

Tuatara is the most over-represented and Kea the most underrepresented, so Kea gets the first empty seat.

This continues, adding one Kea at a time until both Tuatara and Kea are over-represented and Kakapo is under-represented, so they get the final seat.

Now, the jungle council represents, as close as possible, the actual preferences of the citizens – which is a huge improvement over the old, first past the post method.

There is, however, one interesting question that should arise at this point:

Exactly who decides which members of the parties get those extra seats?

The way it works is that, before the election, the political parties make a list of their favorite candidates in the order that they want them to get on the council.

So, if there is only get one extra seat, the name at the top of their list is chosen. If they get two seats, the first two are chosen, and so on.

This makes MMP a bit different from other voting methods in that it makes political parties an official part of the way the election works.

This may give the party leaders greater control over their members because they can reward or punish their actions by changing their placement on the party list.

While this may be a disadvantage of MMP there are a number of other benefits that Queen Lion, in particular, likes.

Because fewer votes are wasted, it mostly Eliminates Gerrymandering and prevents minority rule.

It also gives more choice to the citizens by encouraging political diversity.

This point is worth expanding on.

Notice how, with MMP, the percentage of votes for the local representatives isn’t the same as for the parties. This is because in the local elections, citizens have to vote strategically.

For example, Kakapo voters don’t like Tuatara at all, but they can tolerate Kea. Since there are so few Kakapo voters they know that their candidate doesn’t have a chance of winning the local election, so it’s really a race between the two big parties. Thus many of the Kakapo will vote Kea in the hope that he might win and be their representative.

However, when it comes to voting for their favorite political party, this strategy doesn’t matter. The more votes a party gets the more representatives it has on the council.

So citizens are free to vote for smaller parties they like like knowing that every vote counts.

Queen Lion reviews her options and decides to switch her Kingdom to MMP. Now, for the first time, the Jungle Council is a true reflection of what her citizens want.