At last, they've given out a Nobel memorial prize in economics for something that could make money for you and me. Eugene Fama and Robert Shiller have, between them, saved me many thousands of pounds. (Lars Peter Hansen, who shared this year's prize with Fama and Shiller, developed statistical techniques that, I'm sad to report, have never made me a penny.)

There have been practical prizes before, of course. Only last year, Al Roth shared in the prize, in part for his work designing ways in which possible kidney donors and recipients could be matched with each other for maximum advantage. Ronald Coase, who won in 1991 and died this September, inspired markets to control pollution. And Thomas Schelling, a winner in 2005 for his wily and practical take on game theory, arguably helped prevent the cold war turning into something more catastrophic.

But hard cash in my pocket is something else. And the odd thing is, Fama and Shiller disagree with each other.