Tripling tobacco taxes around the world could cut smoking by a third and prevent 200 million premature deaths by the end of this century, researchers claim.
The tax boost would encourage people to quit smoking rather than switch from more expensive to cheaper brands, and help to stop young people taking up the habit, say the scientists.
They came to the conclusion after conducting a systematic review of 63 studies on the causes and consequences of tobacco use in different countries.
Research has shown that a 50% higher inflation-adjusted price for cigarettes reduces tobacco consumption by about a fifth, with the biggest impact on the young and poor.
In most high-income countries, about 50% to 60% of the price of a pack of cigarettes is tax. But in most low and middle-income countries, tax makes up only 30% to 40% of the cost.
Study co-author Professor Sir Richard Peto, from the charity Cancer Research UK, said: "The two certainties in life are death and taxes. We want higher tobacco taxes and fewer tobacco deaths. It would help children not to start, and it would help many adults to stop while there's still time.
"Globally, about half of all young men and one in 10 of all young women become smokers, and, particularly in developing countries, relatively few quit. If they keep smoking, about half will be killed by it, but if they stop before 40, they'll reduce their risk of dying from tobacco by 90%."
He added: "The international tobacco industry makes about £30 billion in profits each year - that's a profit of approximately £6,000 per death from smoking."
As well as cutting consumption by a third, tripling tobacco taxes would also increase global government revenues from tobacco by a third, from £180 billion a year to £240 billion, said the researchers.
In the European Union, a doubling of cigarette prices would prevent 100,000 deaths a year in the under 70s, they added.
The findings are reported in the latest issue of the New England Journal of Medicine.
Dr Harpal Kumar, chief executive of Cancer Research UK, said: "Worldwide, around half a billion children and adults under the age of 35 are already - or soon will be - smokers, and many will be hooked on tobacco for life. So there's an urgent need for Governments to find ways to stop people starting and to help smokers give up.
"This immensely important study demonstrates that tobacco taxes are a hugely powerful lever, and potentially a triple win - reducing the numbers of people who smoke and who die from their addiction, reducing the health care burden and costs associated with smoking and yet, at the same time, increasing government income.
"We urge all governments, not least the UK Government, to take action by regularly raising tobacco taxes above inflation, and using occasional steep tax hikes starting with the next budget."
A Government spokesman said: "Smoking is the single biggest cause of preventable illness and premature death, and the Government is taking action to significantly reduce the number of smokers in the UK.
"There is clear evidence that cost has an impact on people giving up or taking it up in the first place and the taxation of tobacco announced at the Budget and action to prevent smuggling of it reflects this evidence."