It didn’t take long for journalists to start trying to show how clever they are as quiz masters.

First cab off the rank was A Current Affair ‘s Tracy Grimshaw who last night asked John Howard and later Kevin Rudd to tell her Australians’ average weekly earnings and the Reserve Bank’s prime interest rate.

Rather stupidly both political leaders answered when they should have taken the advice I proffered almost a month ago in Crikey: “the truly clever politician would refuse to play this rather silly game and both John Howard and Kevin Rudd should forget their vanity and develop a form of words that enables them to sidestep idiot questions; say something like ‘running the government of Australia is not a memory test and I’m not Barry Jones and I don’t play quizzes.'”

Despite my advice, Kevin Rudd came unstuck soon after by not being able to name the income levels at which the tax rates change. At least on ACA he showed a sense of humour, prefacing the questions to come with a smiling “this worries me already” before giving two more or less correct answers – $58,000 (the ABS trend estimate for full-time adult total earnings as at May was $1, 134.30 a week or $58,983.60 a year) and 6.5%.

Mr Howard frowned rather than smiled before plumping for $50,000 and 6.25% and positively scowled as the interview ended with him being told he had the interest rate wrong. It could have been worse. Ms Grimshaw could have told him he failed both questions.

And I suppose there was a sort of rough justice involved in the Prime Ministerial mess-up because his anointed successor, Peter Costello, could not resist making fun of Mr Rudd on 19 September for not being able to tell a journalist what the tax rates and the tax thresholds are in Australia. Perhaps he should now send Mr Howard a copy of the Hansard in which he said “this would be amusing if it were not serious”. And then:

He is … on trainer wheels—not coming to grips with economic policy, not understanding it and not being able to look the Australian people in the eye and say that he has an economic plan. He has no plan because he has no understanding.

For if the description applies to a politician who does not know the tax scale it seems more than apt for one who does not know the current Reserve Bank interest rate.