$40 a tonne?

Origin Energy chief says low carbon price will encourage future investment in coal-powered plants 

I saw this interview with Grant King on Sunday, talking about how you would actually need a carbon price of about $40 a tonne to make developing new coal fired power stations unattractive.

This sort of figure has been bandied about before, and given the state of the European ETS price, it makes you wonder why economists like John Quiggin seem so relatively relaxed about Australia joining up to that scheme.

I really don't understand. 

But, on the other hand, I still am yet to hear any economist in the land argue that the Coalition direct action plan is an efficient way to do what it claims to want to achieve.