NSW Premier Mike Baird has been using misleading statistics to defend the success of the state government's lockout laws, the director of the NSW Bureau of Crime Statistics and Research, Don Weatherburn, says.
Following mounting criticism in recent weeks, Mr Baird wrote a lengthy post on his Facebook page on Monday saying that alcohol-related assaults in Kings Cross were down by more than 60 per cent since lockouts and early closures were introduced in February 2014.
He said assaults in the CBD were down 42.2 per cent, while the number of small bars opening had doubled.
However, Dr Weatherburn said Mr Baird was off with his calculations.
He said Mr Baird had compared the situation directly before and after the lockout laws were introduced in February 2014, but assaults had already been declining since 2008.
When the existing downward trend is taken into account, the decrease since the lockout laws is closer to 45 per cent in Kings Cross and 20 per cent in the CBD.
"You can't really compare before and after if the assaults are already down," he said on ABC Radio.
"What the lockout laws did was accelerate that downward trend so it fell even faster after the lockout laws."
Dr Weatherburn told Fairfax Media that the bureau had now analysed 16 months' worth of data following the introduction of the laws, which included 3am closing times for all licensed venues and 10pm closing times for all bottle shops.
He said there had been no change or very little change in alcohol-related assaults for the rest of NSW and no displacement to areas just outside the lockout zone such as Newtown, Double Bay, Bondi or Surry Hills.
There has been a small increase in Pyrmont, particularly around The Star casino, which is exempt from the laws.
Dr Weatherburn said that there had been anecdotal reports from partygoers and venue owners about increasing violence in Newtown, but the statistics did not reflect this.
"There is huge seasonal variation in a place like Newtown; the numbers will go up in summer and down in winter so it probably looks like it's getting worse or better. But has it changed statistically? The answer is no."
The findings build on a BOCSAR report released last April analysing the first eight months of data since the lockout laws were introduced. Adjusting for the pre-existing decline, it found that assaults in Kings Cross fell by 32 per cent and in Sydney's CBD by 26 per cent.
A spokeswoman for Mr Baird said both sets of numbers were accurate and were "measuring different things".
"Whichever you choose they are both an extremely positive outcome," the spokeswoman said.
