I don't think it will; I think the opposite. I think it will encourage parties to be national.
Right now it's tempting for parties that run consistently second or third and don't get any representation in the House of Commons to focus just on the region in which they have strength. That has always been a temptation. Fortunately, the Conservatives have resisted that temptation and have worked hard—in Quebec, for instance—to make themselves a national party. It's the same with the Liberals, who almost got locked out of the west for a while.
I think a PR system would really encourage national parties. The threshold level is very important. When you're taking your evidence in on other systems—we talked about the low threshold in the Israeli PR system—you should consider that, and you should look at the evidence of the proliferation of parties: it's not there. It should be evidence-driven.
There are not big proliferations of regional parties in the countries that have adopted PR, and first past the post countries have even more. That point has been made.