Royal commissions are big and important inquiries, and are a vital part of our accountable democracy. They shouldn't be used for populist or political reasons: doing so just cheapens the mechanism, and some of the more notably successful royal commissions of recent years, including Aboriginal Deaths in Custody and Institutional Responses to Child Abuse point to the value of the institution.

Big, weighty inquiries into matters of huge public importance, as I said.

Behavioural finance explains why the free market doesn't always deliver the best outcomes to consumers.

So when calls started for a banking royal commission, I was unimpressed. Yes, there was evidence of customers being let down (or worse) by some of our largest banks. And there was a not insignificant financial cost to certain individuals and to customers overall who paid too much, or received too little.

But a royal commission? I don't think so. Or, more accurately, I didn't think so.