Easter Egg Hunt

Today while browsing a metropolitan daily newspaper I discovered what one of our state governments had been up to over Easter.

In 24,266 random roadside breath tests the state police found 90 people who were over the blood alcohol limit and 12 who were over the drug limit. The blood alcohol limit is 0.05 g/100mL and I have no idea what the drug limit is or how it is measured - but I would like to know.

So 102 hapless individuals copped a penalty of some sort - probably multiple penalties actually - including loss of license and a heavy fine - all because of an arbitrary number that they happened to be on the wrong side of.

And the blood alcohol limit is a very arbitrary number. It was reduced in 1991 from another arbitrary number (0.08 g/100mL) to the present number. There has been quite a bit of analysis since that time on the effect of changing the number - one set of conclusions states:

"It is not possible from the data to demonstrate that the reduction in the legal blood alcohol level from 0.08 to 0.05 had any meaningful effect on drink driving at blood alcohol levels of 0.08 or above, nor could any such effect be discerned among drivers involved in accidents."

The cynical amongst us might conclude that the reduction from one arbitrary number to another was a "political" exercise designed to appeal to the wowsers - probably also with an eye toward increased revenue via more and bigger fines. The road safety programme seems always to be looking out for the state revenue office ;-)

Not one of these 102 hapless individuals actually caused a problem for anyone. They didn't crash their vehicle or run over anyone or put anyone in hospital or cause anyone any pain - except perhaps for themselves. And the truth is that had they not been intercepted then they most likely would not have caused a problem later in the day. Those are the inconvenient statistical facts.

Now some questions.

1) Why pick on 0.05 or 0.08 for that matter? If the state is going with arbitrary numbers then what is wrong with 0.0 or even -0.05 or for that matter 0.031415927? Actually the latter makes most sense - its PI/100 ;-)

2) Where is the Benefit/Cost in all of this? If the interception of 102 individuals requires the police to conduct 24,266 tests then the cost seems to be way out of proportion to the benefit? A 0.42% hit rate is not a good look in terms of resource usage. Perhaps this state has more money than it needs and Kevin should claw back some more GST?

3) A simple analysis (say $50 x 24,266) shows that costs were likely to be way over $1.20 million to conduct this "Easter Egg Hunt". Wouldn't that money be better spent chasing down some real criminals? Or even investing in a road safety programme that was able to deliver some real tangible benefit?

Just asking.