Dear Economist,

It was my birthday recently and I made some resolutions: to slim for the beach, read more serious novels, save money and quit smoking. I am doing OK on the cigarettes so far but I am already back to watching Big Brother and I have put on 3lb. Did I take on too much at once?

-- Rebecca Furniss, Parson’s Green, London

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Dear Rebecca,

An interesting new paper by three University of Michigan economists argues that willpower is a scarce resource like any other. You cannot exceed your allocation of willpower any more than you can buy a round of drinks with an empty purse.

It’s a plausible view: economic psychologists have found that people make more impulsive decisions if they have already had to resist earlier temptations than if they come fresh to the chocolate bar. Many of us have caved in and given ourselves a “reward” after a day of hard work.

It seems likely that your success in kicking the smoking habit has drained you of the psychic resources to read anything other than Dan Brown. Worse, were you to redouble your efforts to plough through something by James Joyce, your cigarette habit might return, leaving you at risk of becoming the most cultured corpse in the morgue.

The solution is clear enough. First, outsource tough decisions whenever you can. Set up an automatic savings plan and cut up your credit card, so you will not have to resist the temptation to spend too much money. Buy food online so that you do not have to walk past the Ben and Jerry’s and use up your valuable powers of self-denial.

And if you ever feel like reaching for the cigarettes again, top up your willpower by reaching instead for the freezer and the remote control.

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