The survey findings are sobering, even if we adjust for the fact that public concerns may have been heightened following the London subway bombings. Even when possible attacks on trains or subways are excluded, more than 80 percent expected at least one more terrorist attack in their lifetime and 55 percent believe that at least one of each type of incident would occur.

It's a puzzle, and we're all waiting for another clue as to what's really going on. It's a question that has nontrivial implications for people looking at the Minnesota and the national economies.