Back in the go-go eighties, Paul Keating learnt he could move the markets with his tongue. He soon became more circumspect.

Peter Costello has failed to achieve the same feat today. He should be more circumspect, too.

At the time of writing, less than 24 hours after the Treasurer warned of a “financial tsunami”, the Australian market is up more than 50 points.

Keating was talking in the early days of deregulation. Costello is talking two decades after Labor began the process of liberalisation that the supposed party of free enterprise was too scared to consider.

Labor’s policies from back then have led to a more robust economy, an economy more able to withstand wobbles and scares – even when they come from the Federal Treasurer.

Costello already looks like an ass, after the way in which he has conducted himself in the leadership competition. He now looks weak and foolish.

Still, he deserves the benefit of the doubt for the way he has kept his hand on the tiller as Treasurer. Until yesterday. Finance ministers shouldn’t go on wrecking sprees.