Clearly, it's still early years, Australia being the first. For some of the others it's just been a year or so that it's been in place. The full benefit is going to be over 20 years. Australia had a post-implementation review to conclude that it's been effective. All the evidence, except that funded by the tobacco industry, points in the same direction. It's intuitive. Billboards increase tobacco advertising. The package is a type of advertising. It increases consumption. It increases the impact of health warnings, the reviews that have been done, and supported by the World Health Organization, on and on.
On February 12th, 2018. See this statement in context.