The tax rebates approved by Congress and sent to President Bush are supposed to stimulate the economy by making more cash available for consumers to spend, yet surveys show that most people plan to use their windfall to pay off debt.

"It presents a financial dilemma," said P.J. DiNuzzo, president of DiNuzzo Investment Advisors Inc., in Beaver. "The best thing for the economy would be for people to purchase goods and services, while the best thing for their household may be to reduce debt."

The $168 billion bill provides tax rebates of $600 for individuals earning up to $75,000 and $1,200 for couples earning up to $150,000. Couples also could receive $300 for each child. People who earn too little to pay taxes also would receive $300. The checks should start going out in May.

Based on scientific and unscientific polls conducted by several organizations that study consumer spending habits, it appears that credit card companies, not retailers, are more likely to benefit from the proposed rebates.

In a Jan. 28 online poll of 1,500 American adults conducted by e-Rewards Market Research on behalf of financial services company American Century Investments, 36 percent planned to use their rebates to pay down debt. Another 27 percent said they would spend the cash, and 25 percent said they planned to save or invest the windfall.

Ben Woolsey, a senior financial analyst for CreditCards.com, said an avalanche of debt payments is bound to help credit card companies, many of which have tightened their credit policies due to losses. However, it also could cause companies to lose income on interest charges.

What's more than likely to happen, though, Mr. Woolsey said, is that people who are already drowning in debt will use the rebate to pay it down and end up charging it back up again.

"People will end up spending the rebate plus more, and that's especially true for those who are maxed out today," Mr. Woosley said.

But what people say they'll do with the tax rebate and what they actually will do are often different stories.

Dr. Stuart Vyse, a professor in the psychology department at Connecticut College and author of "Going Broke: Why Americans Can't Hold On To Their Money," said when people expect a windfall in the future they often plan to make wise use of it, like saving or paying debt.

"When it gets in their hands, suddenly other needs and desires may influence that decision," Dr. Vyse said. "In the present, there are temptations. You can do things immediately for results. In the distant future, you think of it in a more rational way."

Bernice Darrah, of Plum, said there will be no temptation for her family to spend the money on frivolities. "There's always medication to pay for and bills to pay. We don't have much for luxuries.

"It's a shame," she said. "We're senior citizens and we don't have a lot of money to spend on anything but food and bills."

Joseph Hall, a retired engineer living in the Hill District, plans to take the tax rebate and simply deposit it in the bank with no specific plans for it.

"I don't plan to make any additional purchases per se, but I would probably be a little looser with the spending," Mr. Hall said. "It's good to know you may have $1,200 available in additional funds. But I don't have any particular spending in mind."

Some academic research dating back to the previous round of tax rebates in 2001 suggests households will spend at least a portion of this rebate on consumer durable goods, which can have a stimulative effect on the economy.

"We expect to see most of that stimulus in the second half of the year," said Robert Dye, a senior economist with PNC Financial Services Group, Downtown. "History shows there will be a boost to consumer spending because of this. Some will go to debt repayment and savings, but a good portion will go to consumer spending."

Around the same time frame as the rebate check, many people also will receive their income tax refunds. So, for a lot of taxpayers, the total jackpot will amount to more than $3,000.

Gregory Karp, author of "Living Rich By Spending Smart," said unless people make a proactive decision, the money will end up going where all the rest of their money goes -- in a checking account and frittered away on who knows what by accident and habit.

"That's a significant amount of money to do something good with," Mr. Karp said. "All this doesn't mean there isn't any wiggle room for splurging, but keeping that splurge to about 10 percent of the money is key.

"My advice is to sit down and think about where the money should go. It's easier to not spend if you have a reason not to spend and that reason stems from your financial goals."