What systems are used for electing (non-US) legislatures?

I understand that there are quite a few different voting systems for national and local parliaments or legislatures. In different countries, how do they determine who is elected to the various legslative bodies?

In the US, the membership House of Representatives is apportioned among the states based on population so the total membership of the House is 435. Each state is divided into Congressional Districts with approximately equal populations. During the Congressional elections every two years, whichever candidate gets the largest number of votes in their Congressional district wins the seat.

Each state has two Senators, who are elected for six year terms, which are staggered so that one-third of the Senate is up for election every two years. When a Senate seat is up for election, whichever candidate gets the largest number of votes in their state wins the seat.

State legislatures use similar systems, except that each legislative house must be elected from districts proportional to population (the “one man, one vote” rule). The members of local legislatures (county legislatures, city councils, etc.) may either be elected from an individual district or ward, or elected at-large from the entire locality.

I believe that some foriegn legislatures use proportional voting based on political parties or other systems. I also understand that sometimes the electoral districts may not contain approximately equal numbers of voters. So, how do the electoral systems that you are familiar with work?

In Canada, the House of Commons and all the provincial Assemblies are elected by “first-past-the-post”. That is, the person with the most votes in each riding wins the riding, even if that person only has a plurality of the votes. This approach has been criticised because it tends to produce majority governments even when the party does not win a majority of the popular vote. There’s no proprotional representation, run-offs, or preferential ballots.

At the provincial level, the ridings are divvied up more or less on equal population, with a tolerance of a certain amount, as set by each province’s elections act. A tolerance of ±25% in one province was challenged under the Charter but upheld by the Supreme Court. There are also exceptional cases, such as ridings in the far north of the provinces, where the population is well below the average size in the southern ridings; the Court has upheld that on the basis that the northern communities have distinct interests that would be swamped if they were merged with the southern ridings.

The House of Commons is a bit more complicated. The seats are divided between the provinces based on their share of total population, but it’s skewed by the fact that each province is guaranteed the same number of seats in the Commons that it holds in the Senate. When a province’s population is so low that it drops below that number, it gets the minium number of seats and its population is not used to determine the ratio of seats the other provinces get. As far as I know, the only two provinces who are currently getting more seats than their population would warrant are Prince Edward Island and New Brunswick.

And then there are the three territories. Each gets one seat in the Commons, which further skews the overall ratio of people per riding.

Here’s the populations, number of ridings, and the population per riding in each province and territory of Canada, You’ll see that there’s considerable variation from the national ratio of population per seat. That is partly attributable to the various constitutional minimums that some provinces enjoy, but also because the population figures are based on the 2001 census, while the seat distribution was based on the 1991 census. The seats will be redistributed before the next election, using the 2001 census data.

Province/   Population*   Ridings** Pop./Riding

Alberta      2,974,807       26         114,416

B.C.         3,907,738       34         114,933

Manitoba     1,119,583       14          79,970

N.B.           729,498       10          72,950

Nfld & Lab     512,930        7          73,276

N.W.T           37,360        1          37,360

N.S.           908,007       11          82,546

Nunavut         26,745        1          26,745

Ontario     11,410,046      103         110,777

P.E.I.         135,294        4          33,824

Quebec       7,237,479       75          96,500

Sask.          978,933       14          69,924

Yukon           28,674        1          28,674

**CANADA**      **30,007,094**      **301**          **99,691**

In Norway, each county (plus the city of Oslo regarded here as a county) is an electoral unit, and is assigned a number of seats in Parliament, with the more populous counties obviously having more seats. Voters cast a ballot for a party, not an individual - the ballots list the candidates according to the order in which they will gain seats. Within each district, seats are assigned proportionally according to the number of votes each party receives.

In addition, some seats are assigned “at large”, which is to say they represent no particular county. These seats are used to balance party representation according to the votes each party got in the nation as a whole.

It’s a complicated system, and it makes it hard to win a true majority of seats, so minority governments, coalition governments, and that Norwegian specialty, minority-coalition governments, are common.

In New Zealand we moved from a first-past-the-post system (one winner per district) to Mixed Member Proportional voting in the nineties.

Each voter gets two votes, one for their local Memebr of Parliament and one for the political party they wish to see elected. There are about 40 ‘party seats’ that aren’t tied to any particular electorate. Once all the individual electorates are determined the party seats are divided up so that each party has the number of seats that is proportionate to their total share of the party vote.

Wikipedia has a list of voting systems by nation, and articles on each system. This should answer most of your questions.