In the lead-up to the law change, the Ministry of Health funded Massey University researchers to find out more about the "social supply" of alcohol to young people, with a view to developing strategies to reduce social supply in anticipation of this law change.
Massey's director of Social and Health Outcomes Research and Evaluation (Shore), Professor Sally Casswell, said the research revealed underage drinkers being supplied by their slightly older mates was an important contributor to the harm young people experienced from their drinking.
"The background for the study was based on our knowledge from our survey data that young people, whose drinking has increased since the early 1990s when liberalisation of alcohol policy began, were often being supplied with alcohol by their older friends and when they were, larger amounts were being supplied than when the supply came from parents," Professor Casswell said.
"We confirmed in this study of young suppliers they are typically supplying large amounts and rarely have parental consent. We were surprised at the extent of the harms experienced by the young people as reported by the slightly older suppliers.
"The suppliers gave a range of reasons for supply, including feeling they had to pay back from having been supplied themselves."
Seven hundred people were interviewed for the study.
Over 70 per cent of the "suppliers" reported that the alcohol they had supplied to people under 18 had caused some harms, including drunkenness and vomiting, absence from school, sexually transmitted infections, physical fights, arrest, injury requiring hospital treatment, and sexual assault. Two deaths were reported, but for privacy reasons, further details could not be given.
"The young suppliers, aged 18-22, interviewed supplied large amounts of alcohol to younger friends, on average the equivalent of 8-10 cans of ready-to-drink beverages, and the majority had not received permission from the parents of those under 18," Professor Casswell said.
"One of the issues highlighted by the research is that these young suppliers feel they have an obligation to supply alcohol, as they were supplied it by others when they were younger. Taking a stand to break this cycle could make a real difference to the experience of alcohol-related harm by those under 18."
Professor Casswell said the findings also provided an opportunity to engage with suppliers on their own terms about the down sides of their supply.
"[The study] will help to ... stimulate publicity and discussion about the new legislation, coming into force in a few days, which tightens up the law against supplying to young people. The results can also inform community action to do the same.
"With the lowering of the minimum purchase age from 20 years to 18 years there is more social engagement between those who can legally purchase and those aged 17, 16, 15 years. This provides an easy option for supply," she said.
"The older ones need to have some way of being able to justify refusing to supply. The law provides one such opportunity. It will help if there are some examples of enforcement of this part of the law."
• A Massey University study revealed people aged 18-22 who supplied alcohol to underage drinkers on average provided the equivalent of 8-10 cans of ready-to-drink beverages.
• Over 70 per cent of suppliers reported the alcohol they provided led to harm including drunkenness and vomiting, absence from school, sexually transmitted infections, physical fights, arrest, injury requiring hospital treatment,
sexual assault and death.