“There’s always tomorrow,” writes Jonathan Clements in todayÕs Wall Street Journal. “We all agree that it is smart to save diligently, spend prudently and invest intelligently. No doubt about it, these are entirely worthy long-term goals. There’s just one drawback: They sure don’t seem very appealing right now.

“For instance, if your spouse suggested saving money by eating out less in the future, you might readily agree. But if your spouse proposed canceling tonight’s restaurant reservation, you would likely balk.

“Ditto for other onerous undertakings, like quitting smoking, revamping our portfolio, losing weight, visiting boorish relatives and cleaning out the garage. We will happily commit to doing all these things — as long as we don’t have to do them today.

“It’s no great surprise that we seek to postpone pain, financial or otherwise. But what’s interesting is how much more amenable we become, if we can delay the cost for just a short while. Often, we happily agree to unpleasant tasks that are months away, only to regret it when the time rolls around. Indeed, at that juncture, we may try to weasel out of our commitment.

“What explains this odd behavior? At issue is our lack of self-control. But that seems to be exacerbated by two behavioral phenomena.

“First, we will pay a surprisingly steep price to get gratification today and to postpone costs until later. If the yield on money-market funds is anything to judge by, we should be indifferent between $1,000 now and $1,037 in a year’s time. But if somebody offered us a choice between a $1,000 vacation next week and a $1,500 vacation next year, it is an easy choice. We will start packing tonight.

“Similarly, if we spot a $1,500 desk in an antique store, we might happily pay the asking price if we can stick the cost on a credit card and delay the day of reckoning. But if the store insists that we pay cash, we might not buy the desk unless the dealer agrees to cut the price to, say, $1,200.

“Postponing costs, of course, eventually catches up with us. It is not just that we discount future pain and pleasure at a surprisingly steep rate. There is a second, related notion of “time inconsistency.”

“ÕThe time inconsistency comes from the fact that the discounting doesn’t have a nice, constant structure,Õ says Ted O’Donoghue who, together with Matthew Rabin, discussed the notion in Behavioral Dimensions of Retirement Economics, a book edited by Henry Aaron. In other words, not only do we discount too heavily, but also we apply an especially steep discount rate to the immediate future.

“For instance, you want to start saving $200 each paycheck, says Mr. O’Donoghue, an economics professor at Cornell University. ÔBut each time you get paid you decide to put it off to the next paycheck. This is something you really want to do. But you may never do it. You have these time-inconsistent preferences.Õ”

“Because of this phenomenon, we may constantly defer key financial decisions, even though we know they are in our long-term interest. ‘It leads to procrastination,’ Mr. O’Donoghue says. ‘When carrying something out seems onerous, people will keep putting it off and planning to do it in the future.'”