Higher prices for alcohol will do little to curb high-intensity drinking because binge drinkers commonly drink little or nothing on some days so they can binge on the weekend, leading public health experts warn.
At the same time, new evidence shows a polarisation of Australian habits, with the heaviest drinkers consuming more than before while light drinkers are consuming less and more people are abstaining.
Concern over alcohol-related violence has prompted demands to increase the price of booze.
But global data shows that, far from being cheap, Australia is one of the most expensive countries to buy alcohol. Of more than 190 countries, discount beer in Australia is the second most expensive and spirits the seventh most expensive. Table wine in Australia is the second most expensive of the OECD countries.
But while price can influence consumption - the cheaper the alcohol, the more people drink - the effect on high-intensity consumption is less clear.
"When you use a blunt instrument like taxation that affects everyone, it doesn't necessarily affect everyone evenly," said Griffith University health economist Josh Byrnes.
Binge drinkers in Australia tend to respond to higher prices by adjusting their buying patterns rather than their behaviour, says a peer-reviewed study led by Dr Byrnes and Anthony Shakeshaft, deputy director of the National Drug and Alcohol Research Centre.
When prices go up, high-intensity drinkers simply have more days when they consume little or nothing to save their money for weekend binges.
"[Binge drinking] is people's preferred way of drinking, so they're going to use the money they spend on alcohol in a way that fits in with their preferred pattern," said Professor Shakeshaft. "If the price goes up and people have less money to spend on alcohol, they're not going to change their drinking behaviour, they'll just find ways to maintain that behaviour."
Meanwhile, new research shows drinking habits are diverging.
"Generally speaking, when drinking changes it changes evenly across the whole distribution. If drinking goes up 10 per cent, heavy drinkers and light drinkers alike are drinking 10 per cent more than they used to," said NDARC researcher Michael Livingston.
"Now what we're seeing is a breakdown of that pattern. We've seen in Australia no real change in [overall] consumption but an increase in very heavy drinking offset by reductions in light drinking."
There is evidence of a sharp decline in teen drinking and lower consumption among the ageing population. "People tend to drink a bit less as they get older," Dr Livingston said. "Our population has a bigger bubble of people in their 60s and 70s, so that consumption's got to be offset somewhere else."
The reason for the change is unclear. Part of the problem is that researchers haven't captured how much the heaviest drinkers are consuming.
“When I started doing a PhD back in 1994, we asked some coal miners in the Hunter Valley what they thought was a binge,” Professor Shakeshaft said. "It was something incredible like 20 standard drinks in a session and here we were asking them how often they had more than 6 standard drinks in a go."
Also, most respondents tend to under-report how much they drink. “In that case, we’re potentially setting the bar too low," he said.
"It could be that the levels of harm we’re seeing now are actually associated with higher levels of consumption than what we think, precisely because people are under-reporting what they drink.”
University of Melbourne sociologist Robin Room, who has directed alcohol and drug research centres in the US, Canada, Sweden and Australia, remembers how US researchers determined "five-plus" drinks as the cut-off which later became the basis for international surveys. "It was because they didn't dare ask about more."