Two years of working in a culture supported by the principles of Positive Behaviour Support left me in no doubt about the complete ineffectiveness of punishment as a tool to modify behaviour.
Here's why: Behaviour is a result of an urge, or desire. Avoiding boredom, relieving frustration, communication, stronger communication, I-really-mean-it, relieving hunger, etc. All urges that result in behaviours. That's why behaviour, and what behaviour, and the key to understanding behaviour.
Which means that if you use punishment to prevent a behaviour you will leave entirely open the question of where the urge will manifest itself next.
The only meaningful way to change someone's behaviour is to identify what the urge is and channel it somewhere else, or head it off early. The threat of punishment has to be pretty severe and pretty imminent to convince people to find their own non-punishable alternative.
This is why incarceration doesn't prevent crime, and why our current society tries so desperately hard to call prison, "corrective services".
All which will explain why I laughed so sarcastically when the alcopops tax was raised. "We must reduce teenage binge drinking!" They said, and penalised already expensive, low-to-moderate alcohol, content-controlled mixed drinks.
And now the spirits industry has confirmed the inevitable: Sales of alcopops are falling but, surprise surprise, sales of neat, strong, bottled spirits has gone up. Sooner or later people will realise that they are now getting drunker, faster, and will thank the government.
Learn from this, Bligh & Co.
Link to ABC Online story: "Spirits industry confirms alcopops sales falling."
(N.B.: I hereby nominate that headline as the most deceptive and unhelpful I have seen this week)