Terrorism in Canada

Q18: Will there be a lethal terrorist attack in Canada in 2015?
Yes: 25%
No: 75%
(Definition note: "lethal", in this context, means that the attack results in the death of at least one person who is not responsible for the attack.  "Terrorist attack" should be construed broadly.  The attacks on October 20 and 22 of last year would have qualified under this definition, as would the attack on PQ leader Pauline Marois in September 2012, as well as all the lethal attacks on this list.  The daycare shooting in Gatineau in 2013 would not count)

The terrorist attacks in October, together with the more recent attacks in France and Australia, have increased the perceived risk of a terrorist attack in Canada.  Looking at the broader historical record, the situation is less clear.  From the Wikipedia list of terrorist incidents in Canada, since 1980, there have been lethal terrorist attacks in 1982, 1984 (2 incidents), 1985 (2 incidents), 1998, 2012, and 2014 (2 incidents).  So there have been attacks in about 17% of years.  Admittedly, this number does not take into account the relative timing of years (the attack in 1982 counts for as much as the ones in 2014).  Assuming the relevance of a year decays with a half-life of 5 years, I get a 25% estimate for 2015, which I will use.

The risk of Islamic terrorism may be elevated due to recent attacks.  This is taken into account by my discounting procedure.  It is relevant here that there were no successful Islamist attacks in Canada following the 9/11 attacks, although the risk level was elevated then as well.