Originally Posted by
Kevin AA
It was my understanding that the reason why so many Canadians hold passports is because most of the population lives within 100 miles of the U.S. border and lots of people go shopping in the U.S. re Australia/NZ, I'm not very familiar with those two countries other than the fact that passport control for residents of one country flying to the other is extremely simple.
Flights leaving from the US are much cheaper than those leaving from Canada, though airports near the border (BTV, BUF/IAG, BLI, et. al) are generally for US domestic flights only.