Smokers completed three questionnaires - one at the "baseline" entry to the study and the others after two of the Government's annual 10 per cent tobacco tax rises.
The quit-smoking rate, at 14 per cent, was the same for the Maori/Pacific and NZ European/other ethnic groupings.
Participants were analysed only in those two ethnic groupings, because there were few Maori and Pacific men and women in the study.
Writing in today's Australian and New Zealand Journal of Public Health, the researchers say that although there was an ethnic difference in women's rates of physical dependence on tobacco, there were no significant differences in one measure of behavioural dependence.
"This is particularly interesting given that smoking rates for Maori/Pacific females are one and a half times those of NZ European/other females.
"It may indicate that behavioural, social or cultural influences are particularly important in maintaining smoking behaviour for Maori/Pacific females, while physiological nicotine dependence may have a relatively smaller contribution," say Megan Tucker, of Canterbury University's psychology department, and her colleagues, who include public health physician Dr Murray Laugesen.
The study found that following the tax increases the number of cigarettes smoked per day and the degree of psychological addiction declined for both ethnic groupings.
It also found that while at the baseline, people in both ethnic groupings smoked around the same number of cigarettes per day on average, after two rounds of tax increases, the Maori/Pacific smokers used significantly fewer than the NZ European/other smokers.
This suggested Maori/Pacific smokers were more sensitive to price increases than NZ European/other smokers.
"This effect appeared to be independent of income level, as both groups demonstrated comparable self-reported income."
Reducing the number of cigarettes per day confers minimal direct health benefits, the researchers say, but it may make a smoker more likely to quit in future.
In the Budget in May, the Government announced it would continue its programme of 10 per cent tobacco excise tax increases each January until 2020.
The New Zealand Government has set a "Smokefree 2025" target that the rate of smoking will fall below 5 per cent by 2025.