You are correct that it is not "necessarily" true that the largest party is part of a government coalition. It is just what usually happens. Under a mixed system, there are still usually two large centrist parties, and one or both of them is almost inevitably the core of the government coalition. This is true under any voting system.

It is not a problem that parties negotiate after the election. That is what we choose our representatives to do for us, and it is what Parliament is supposed to be all about. Imagine, we could have a Parliament where real debate happens and real decisions are made!

The suggestion that coalition governments produce less coherent policies will not stand up to scrutiny in the real world. Most developed countries have proportional voting and minority/coalition government, and have had for most of the last century. They tend to have lower inflation and unemployment than we do, better social services, greater satisfaction with politics and politicians, and higher voter turnout.

This is all remarkably well informed and balanced, so I'll settle for a quibble:

"A fully proportional election scheme requires the use of ordered party slates, and the election of deputies who are answerable to no geographic base, no particular group of voters, at all."

A province is a geographic base, and so is a country, and the people who live there are a particular group of voters. A deputy elected on a national list is accountable to every voter in the country.

In practice, everybody comes from somewhere, and people tend to vote for the local guy. List systems create remarkably good geographical representation. List members in mixed systems tend to have constituency offices and deal with constituency concerns. The government still goes to the party that wins the most ridings (because the party with the most votes will win more than their share of ridings), and the list seats are consolation prizes for the losers. And the riding seats are the safe seats, so list members are always working to establish a constituency base and become a riding member.

Almost all of us, like 90-95%, vote for a political party (or for a leader, which amounts to the same thing). But the wasted votes inherent in winner-take-all voting horribly distort the results of every election in this regard.

Most of us are "represented" by somebody we voted against, and most MPs "represent" mostly people who voted against them.

Usually one political party gets all the power, even though most people voted against them.

The Bloc gets twice as many seats as the NDP with half the votes.

The Green Party (or the Reform Party in Ontario) gets a million votes and elects nobody.

Half a million Liberals in Alberta elect nobody. Half a million Conservatives in Toronto and Montreal elect nobody.

And so on.

It is absurd to suggest we get what we vote for under the current system.

It may be that the way to go is to get a referendum in favour of the principle of proportional representation first, and work out the details later. I think that's how they did it in New Zealand.____Those who so ardently defend the status quo are good at picking out flaws in particular proposals, but it's hard to argue against the idea that we should get what we vote for.