Mr Geithner looks a lot younger than his 47 years (though not as young as he did before the crisis began). He skateboards and snowboards and exudes a sort of hipster-wonkiness, using "way" as a synonym for "very" as in "way consequential" and occasionally underlining his point with the word "fuck". In temperament he seems similar to Mr Obama: he is suspicious of ideology, questions received wisdom, likes a competition of ideas and is keenly aware of how uncertain the world is.
He is a quick learner: within a year of joining the New York Fed he could debate the intricacies of monetary policy with academic experts. But he will join an Administration rapidly filling up with heavyweights on economic policy, not least of them Mr Summers. Indeed, one of the big questions of the new team that Mr Obama is expected to unveil on Monday is just how Mr Summers, a brilliant but intimidating and sometimes abrasive figure, will fit in.
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