[jfengel]

Multi member districts does circumvent one of the assumptions of Duverger's Law, which predicts a two-party system.

But you still need to work around collusions between candidates. Candidates will be pushed to run on a slate of N candidates for N seats, and promise to support each other. Voters who want any of their positions will avoid somebody who would interfere with their own top priority. The result acts the same as a two party system, where all N candidates support the same party.

You can get some benefit by combining it with List Voting, where you go ahead and reify the party system. The party gets to send whoever it wants, proportional to the votes.That makes it harder to run multiple candidates that take all of the spots. (Not impossible: they can break into multiple virtual parties. But that's risky and coordinating votes is difficult.)

Even at that I'm not sure it really helps. Lawmaking is still fundamentally a "single member" operation: a bill either passes or it doesn't. You still get pushed to be in either the majority or minority coalition.

[johngladtj]

>Even at that I'm not sure it really helps. Lawmaking is still fundamentally a "single member" operation: a bill either passes or it doesn't. You still get pushed to be in either the majority or minority coalition.

The solution for that is to not make it a simple binary pass/fail, but to have how it passes and fails affect the outcome.

A simple and consistent way of doing this is by making it so that all laws have a built in expiration date, and how big the majority for passing the bill affects how long the law is in effect from.

A 50% + 1 margin of victory should result in the law becoming void the moment the parliament composition changes.

Perhaps a 60% margin might allow it to go for 10 years, a 70% margin for 15 years, and so on.

Constitutional changes should essentially require unanimity ( and a referendum on top of it) since they are the only permanent laws.

Some laws would be more or less "permanent" since every 30 years or so you'd like get a 99%+ majority for a "theft is illegal" type low, but other more controversial would likely be on the ballots every few years.

[theluketaylor]

> A 50% + 1 margin of victory should result in the law becoming void the moment the parliament composition changes.

I do like the idea of built in timers on laws, but instant revocation seems too extreme. A marginal law expiring at the end of the new term seems more conducive to stability. That gives time to debate, discuss, and pass (or not) a modified version so everyone affected has time to participate and plan for revisions.

> Constitutional changes should essentially require unanimity ( and a referendum on top of it) since they are the only permanent laws.

Here in Canada the bar on constitutional amendments has been set so high it's unlikely we will ever be able to change it for any reason. Too much change isn't healthy, but neither is none.

Not American, but I do think their bar for constitutional amendments has also been set too high and I think it's contributing to polarization. Setting it even higher seems counter-productive. I have similar feelings about the filibuster.

More laws passing would let people live with the consequences, good or bad, of all the stuff being proposed. Voters would be able to vote based on reality rather than the boogey-man each side portrays of what the other side might do with power. There should be a high bar to change a constitution, but it needs to be clearable more often.

[dragonwriter]

> But you still need to work around collusions between candidates

No, you don’t, if it’s a multimember proportional system, like STV. There are some multimember systems your concern applies to, like the “vote for N, top N win” at-large system used for some US city councils, school district boards, and similar bodies: those are simply means to have a multimember body while avoiding either diffuse or geographically-concentrated minorities from being represented. (And the prospect of that particular kind of multimember arrangement being used to neutralize the effect of black voting rights, specifically, is why multimember districts are prohibited by federal law in Congressional apportionment, currently.)

[theluketaylor]

I'm really against mixed-member proportional (and pretty much all form of proportional representation) since you end up with party hacks unaccountable to voters. When parties control the order of the lists there is also really strong incentive by representatives to tow the party line to avoid relegation.

[dragonwriter]

> I’m really against mixed-member proportional (and pretty much all form of proportional representation) since you end up with party hacks unaccountable to voters.

Candidate-centered proportional systems (e.g., single transferrable vote in moderately sized, 5-7 member, districts) do not have this problem of party-list/MMP systems, though they have somewhat less finely-grained partisan proportionality (limited by district rather than legislative body size.) OTOH, they are still potentially effectively more proportional because the general electorate preference for individual candidates captures more dimensions of both policy and non-policy preference than mere party preference captures.

It’s also possible to have the party lists being ranked by general electorate preference (especially in MMP, rather than full-body party list PR, because in MMP the list is only used for top-up seats which requires smaller, more manageable lists.)

[JanisErdmanis]

It can still be made possible for the voters to rank the candidates within the list. This is true in Latvia where we do add +/- for each candidate in the list that eventually determines their rank. The elected candidates sometimes do change their parties when elected or become independent if they no longer want to follow the party line.

[tanewishly]

I must be not quite following your explanation... In most of the EU, there are multi-party systems. From what I can tell, that is because of multi-member districts. Eg. The Netherlands has only one district for parliamentary elections (150 seats). There are more than 2 parties in Parliament there.