For those who can't get enough debunking of the Helena, Montana, smoking ban study, here are some problems I didn't have space for in my column:
The heart attack data do not really match the story the researchers are telling. Starting at the beginning of 2002, the pattern was:
The ban took effect in early June and was suspended in early December. Notice that the 8, 6, 2 sequence appears twice in a row; the tail end of the second sequence happens to fall in June, at the very beginning of the ban. There's no reason to assume that the low number seen that month had anything to do with the ordinance.
Also, it's implausible that the ban would have its greatest impact early on, when compliance and enforcement were spottiest. The local paper was still running stories about the need to crack down on noncompliant establishments in late September. And why would heart attacks rise and go down again in the middle of the period when the ban was in effect?