Most people agree that tobacco is harmful to health, but many people still smoke (see Wikipedia statistics). Many drugs such as heroin are illegal but still taken by a significant number of users (see a recent Guardian story on UK consumption).
Governments seem to believe that scaring people about the degree of harm they will experience is an effective technique to reduce consumption of substances harmful to health (legal or illegal). For some recent advertising see here, and an interesting collection here.
It seems "obvious" that scaring people should be an effective technique here. But the effectiveness has been questioned (see US story reported by USA Today or the UK story reported by the Guardian). And skeptics don't just accept the obvious, we want to see evidence.
So, my question is simple: do scare tactics work to discourage use of harmful things in today's world?
NB I think it will be important to be clear about the context. I suspect that scare tactics do work on some people, so, when we didn't have a clear idea of how bad tobacco is for health I suspect many people would have stopped smoking when the evidence of harm arrived. The question is about now: it is hard to imagine that any smoker (or drug user) is delusional enough to deny the harms of their habit. So is there any evidence that their consumption will be reduced further by scare tactics?