Smoking could "virtually disappear" in New Zealand and many other developed countries within half a century, according to research by a major investment bank.
But Citigroup reckons the habit could be almost wiped out in Australia in as little as 20 years.
Smoking prevalence is 17 per cent in Australia and 19-20 per cent in New Zealand, depending on the data source, although Citigroup puts the NZ rate at 18 per cent.
But even if New Zealand has gone smokefree by 2061, the epidemic of smoking-related disease and premature deaths for many smokers will linger.
"The deaths stop 20 to 50 years after smoking ends," Christchurch public health researcher Dr Murray Laugesen said.
He said the Health Ministry estimated before the Government announced its tobacco tax increases last April that New Zealand smoking prevalence would drop to 9 per cent by 2051. He calculated that the tax rises could shave off a further 3 percentage points.
Tobacco control groups were predicting before the tax announcement that on the current rate of decline in smoking, it would take 70 years for NZ to become smokefree.
But following the announcement - and Parliament's Maori affairs committee recommending in November tough new policies with the aim of NZ's becoming smokefree by 2025 - they are much more hopeful.
"We have the vision that it can be done by 2020," said Prudence Stone, director of the Smokefree Coalition.
Citigroup said the percentage of smokers was declining throughout the developed world, "more or less in a straight line in most markets. If these trends continue, then by 2050 many important tobacco markets will have gone to zero smoking".
Britain's Guardian newspaper said the analysts outlined three scenarios they considered plausible: the graph continuing until it hit zero; gradually fewer people quitting, leaving a hard core of smokers; or smoking reaching a tipping point, after which it became increasingly unacceptable and might eventually be banned.
In New Zealand, the Government is expected to formally reply early next month to the Maori affairs select committee, whose recommendations included annually reducing the amount of tobacco for sale by a set percentage, requiring tobacco to be sold in plain packaging with health warnings, improving access to quit-smoking help, and banning retail displays of tobacco.
The Government has already introduced legislation to ban retail displays and to permit instant fines for selling tobacco to minors.
Smoking restrictions are being introduced at many parks and playgrounds, and music fans at next week's Big Day Out extravaganza at Mt Smart Stadium will be asked not to light up, although the venue operator says people who defy the five-month-old ban will not be ejected.
Citigroup's predictions for the end of smoking:
Sweden - 2028
Australia - 2030
Iceland - 2033
UK - 2040
US - 2046
NZ - 2058
Italy - 2091
France - 2118
Greece - 2231
Germany - 2280