Here I am listening to a radio broadcast of a panel discussion between several political candidates in our impending general election. It’s a well run discussion (thanks to the skills of Wallace Chapman), and unlike some similar events, everyone is behaving well so we all get to learn a lot about who thinks what about what. This is good.

But what I’m more interested in here is not so much the specifics as the pattern they take. For example there is a question about what the voting age should be. Currently it is 18. I remember (just) when it was 21. Should it be higher? Should it be lower? What do you think?

This seems a good question, certainly worth asking. At 18 we can sign contracts, marry (actually we can do that at 16), vote, buy alcohol and join the army. We don’t have any need to conscript soldiers just now, but when we have had such a need it has been tied to the voting age on the understanding that if you’re not old enough to vote you’re not old enough to be made to risk your life for your country.

So the panel tossed the question back and forth with answers starting with ‘well I think…’ and speculating that some younger people are old enough to vote and perhaps they should. Then others think it is about right or maybe could be higher, especially with alcohol purchasing.

What no one suggested is actually studying the people involved. Do we have any good data on how well informed 10 year olds actually are? 12 year olds? 14? 16? 18? Surely this is critical to setting the age. We know from other studies that IQ has been shifting upwards for years. This is called the Flynn Effect (Flynn is a New Zealand scientist, but the effect is observed world wide). So it is not unreasonable to suppose that our understanding about how younger people make decisions is out of date.

Step back a bit, though. This is really not about the specifics. It is about gathering data. It is not enough to base policy on ‘well I think…’, and it seems we do too much of this. What any of us ‘think’ about some issue is far less relevant than what the data says.

Another example just to round it out: we have a minimum wage in NZ. Some people think it should be raised, others want to scrap it. The latter tend to say that raising it will cost jobs. This is a ‘well I think…’ statement. It is very easy to show data that raising the minimum wage does not cost jobs by looking at what has happened when this was done elsewhere. I’ve yet to see a study referenced that shows it has cost jobs. Maybe there is one, but let’s see it instead of having people say ‘well I think…’

So watch out for people saying ‘well I think…’. If you can, ask them why they think that. Press them for data, some reference to some properly conducted study that demonstrates what they are saying is true (or at least not false, which is subtly different but okay). If you want to pursue this further get hold of Karl Popper’s The Open Society and its Enemies which is about some other things as well but he argues better than I can for evidence based policy. Popper wrote this while he was lecturing in Christchurch, NZ during WWII (as an Austrian Jew he needed to leave Europe, but his German heritage made him unwelcome in the armed forces on our side). So there is a local connection there too.