It's entirely possible that the man from the Post Office is right here. That instead of banking when in credit being free, with high charges for not being in credit, it would be better to have a system where all get charged the costs of their activities. Entirely possible that he's right: Free bank accounts are unfair to poor customers and form an unsustainable foundation for the banking system, according to Post Office Money’s chief executive, Nicholas Kennett, who wants to see the industry charge customers regular fees instead.

He believes it is unfair that customers who have to use their overdrafts are charged high fees, which are then used by the bank to offer free accounts to the better-off who rarely pay any fees.

We also have a system to work out whether he is right:

While this may mean that customers who never incur fees and charges are well-served, he argues that charging customers for the services they use would be fairer overall and lead to better service for more account-holders.

In his case, the Post Office offers an account which costs £5 per month and will not let customers rack up unexpected overdraft fees.

Excellent. So, those who think that is the better system will flock to the Post Office to gain access to that better system. Those who do not will not. No one need do anything else. The alternatives exist, all are free to choose between them so choose people will. Which is the best system thus being not something that we can determine a priori, but something emergent from what people do.

You know, this market stuff?