From Professor Sinclair Davidson of RMIT University in Australia:
“I have no doubt that the consumption of cigarettes has risen since plain packaging was introduced; we just can’t be sure whether it is by existing smokers or new smokers.”
The quote's from an excellent article in The Australian (via Chris Snowdon). We should be clear that the good professor isn't saying that plain packs caused the rise in consumption rather that there's no link between what the packs look like and levels of consumption. Something some of us were saying even before the Aussies introduced the policy.