A debate has flared up again about whether cost is a major factor in smokers deciding to quit.
Only 11 per cent of smokers contacting Quitline cited the cost of cigarettes as a main reason why they decided to give up the habit, the organisation's chief executive, Andrew Slater, said.
An excise tax introduced in last year's Budget will increase the price of a pack of 20 cigarettes from about $20 to more than $30 by 2020.
But University of Otago professor Janet Hoek said there was "strong evidence'' the tax was encouraging smokers to quit.
Ministry of Health data showed the number of smokers in New Zealand had decreased from 20.1 per cent in 2006-07 to 16.3 per cent in 2015-16.
According to Quitline data, 45 per cent of people who quit smoking said health was the main reason.
This was in line with Anglican Family Care director Nicola Taylor's belief that education could decrease the number of smokers.
The debate has re-emerged after several recent widely reported tobacco thefts in Dunedin.
A rifle was used in the robbery of the Halfway Bush Convenience Store this month, and a Palmerston store, Mobil Forbury and Mobil Eastgate were also robbed recently.
Ms Taylor said tobacco thefts were "not a new behaviour'' and maybe there was not just "one simple solution'' to reducing smoking rates.
"[We are] very aware of the real tension with the cost of tobacco.''
She said the issue with encouraging people to quit smoking was that putting prices up did not necessarily make people change their behaviour.
"There has to be a decision from the person to change.''
Acting Inspector Ben Butterfield, of Dunedin, said police did not collect data on individual items stolen in thefts and it was difficult to determine whether the number of tobacco thefts was increasing or they were just becoming more high-profile.
A variety of "social factors'' drove up offending and crime rates, but police could not comment on the cigarette tax scheme because it was a government decision, he said.
Methodist Mission director Laura Black said the fact packets of cigarettes were "small, transportable and people were willing to pay'' for them made them an easy target for thefts, whereas buying "$30 worth of watermelons'' would need a trailer.
Professor Hoek, who specialises in tobacco control, said one option of limiting the risk to dairy owners was to restrict the sale of tobacco to specialised R18 stores.
She was also sceptical of the theory tobacco was being stolen and traded on a black market.
In a survey of 30 low-income smokers she had conducted last year, only one person had said they had ever bought or been offered illicit tobacco.
"The people who are putting out the black market [theory] are tobacco companies.''