Refunds mailed so far this year average $2,292, a 4.5 percent increase over refunds mailed at the same time in 2003. Tax refunds tend to be higher during the first weeks of the tax filing season, when taxpayers expecting checks hurry to file their returns.

"It's significantly higher than it was a year ago, and that's one of the tail winds pushing the economy forward during the first quarter," said Sung Won Sohn, chief economist with Wells Fargo & Co., a banking company in Minneapolis.

Last week the Treasury Department said, "The president's 2003 tax relief will increase refunds paid this spring by an average of $300."

Treasury Department spokeswoman Tara Bradshaw on Friday clarified that figure, saying the average $300 increase compares this year's expected refunds with projections of the refunds taxpayers would have gotten this year had last summer's $330 billion tax cut not passed.

Some economists monitoring the refunds said they expected a bigger increase than they've seen so far. The economists said they can't fully account for the lower-than-expected refunds but cautioned that the numbers may quickly change.

"It does look like it's a little light, but I think it's just too early to tell," said Joel Prakken, chairman of Macroeconomic Advisers LLC, a St. Louis forecasting firm. "I don't have alarm bells going off."

Prakken said taxpayers can expect to get between $40 billion and $50 billion returned this spring, the proceeds from reduced taxes on dividends and lower income tax rates enacted too late last year to be completely incorporated into paychecks. Whether the money comes in the form of bigger refunds or lower tax bills remains to be seen, he said.

Other economists said refunds might be coming up smaller than they expected because of new tax complications, lower incomes and even lower interest rates.

"It may be that it's taking people longer to file taxes because it's still more complicated this year," said Cynthia Latta, principle U.S. economist at Global Insight.

Last summer's dividend and capital gains tax cuts, in particular, added complications to this year's tax forms. Investors must sort out which dividends qualify for the lower tax rates and determine whether their capital gains must be taxed under the old system or the new rates.

Taxpayers might also be seeing lower interest rates taking a bite out of their tax deductions. Homeowners who took advantage of rock-bottom interest rates to refinance their home loans during the last several years might be taking smaller mortgage interest deductions.

"Refinancing activity was stratospheric last year," said Mark Zandi, chief economist at Economy.com, an analysis firm. "There's a a lot of interest savings, cumulative interest savings. It may be having some impact."