This great article by University of Toronto professor Lawrence Leduc ran in the Globe & Mail this week.
Here's an excerpt:
Some criticisms of MMP that have been advanced don't stand up to close scrutiny. It's probable that one or two more parties will gain representation in the legislature than under the current system. But this is what should happen when significant numbers of voters support them. It's also probable that there will be coalitions, at least some of the time. Governments that do not have to compromise become arrogant and unaccountable, but, under MMP, all parties will quickly learn that it is their job to make the legislature work, not merely to hurl insults or plot election strategies.
Germany, which has the longest experience with MMP, has consistently had stable and effective coalitions. A CDU-FDP coalition was in office during the 1980s and 1990s, and was replaced by an SPD-Green coalition in 1998. In 2005, a “grand coalition” of CDU and SPD came to power. All those governments were led by pragmatic, centrist leaders: Helmut Kohl, Gerhard Schroeder and Angela Merkel.
In Scotland, a Labour-Liberal coalition was recently replaced by a single-party Scottish National Party minority government. New Zealand, which adopted MMP after a 1993 vote, has had stable coalitions since 1996.
The idea that MMP will empower extremists or produce unstable governments is a myth, largely promulgated by those with a vested interest in the existing system.
The fact that MMP was recommended by the Citizens' Assembly gives it considerable credibility and legitimacy. They recommended a model constructed with Ontario's needs clearly in mind. This body of 103 men and women arrived at their recommendation after eight months of study, debate, discussion and public consultation. They did not come to their task with preconceived ideas about electoral systems but ultimately recommended MMP by a 94-8 vote. This has been a consistent pattern in other debates on electoral reform.
If Ontario voters examine the system carefully before they vote, MMP will surely pass. Its opponents will offer hoary clichés about Italy or Israel, or conjure up highly improbable scenarios about extremists. But if the voters are smart, as I believe they are, they will seize this rare opportunity to empower themselves.