How much cigarette prices have to rise to get most smokers to quit

Research has revealed increasing the cost of cigarettes by $15 could lead to students cutting down on smoking.

The University of Canterbury study analysed the smoking habits of 187 current smokers to see how their behaviours change with the price.

They found an increase of $15 is enough for people to switch to e-cigarettes or quit altogether. 

"Quit intentions increased at all price levels, but were stronger among younger students and females," the study, published in the New Zealand Medical Journal on Friday, concluded.

"Males were almost twice as likely to switch to e-cigarettes as females. Overall, more students would quit than switch to e-cigarettes."

About 5000 people die a year from smoking-related illness or exposure. Despite years of campaigns and price hikes, and the growing availability of e-cigarettes, around 14 percent of all Kiwi adults still smoke at least once a month.

Last year, the average price of a packet of 25 cigarettes was $37.48, according to Statistics NZ. Increasing that by $5 would only get 7 percent to quit, and more than half would keep on smoking the same amount, the research found. Raising prices $10 only saw small increases in those willing to quit or switch to e-cigarettes.

But upping it by $15 in one go would see a fifth switch to e-cigarettes and two-fifths stop altogether. Only 17 percent - fewer than one in five - would keep smoking the same amount.

"While the findings support research hypotheses (reductions in smoking; increased switching to vaping, and increased quitting, when prices increase), actual behaviour changes may be influenced by nicotine dependence, knowledge and use of tobacco alternatives such as e-cigarettes," the study said.

New Zealand has a goal of being smokefree - defined as fewer than 5 percent of people smoking - by 2025.