Michael Shreve, a 57-year-old science teacher in Marysville, Wash., has watched helplessly as mortgage rates have fallen. He said that despite his stellar credit score, no bank had been willing to let him trade in his 6.35 percent 30-year mortgage because his house was now worth less than when he bought it.

“At some point,” he said, interest rates are going to go up again, “and I should have been able to get those low rates. It’s not fair.”

As interest rates have been dropping to new lows seemingly by the week, U.S. companies have been taking advantage of the cheap borrowing costs, but consumers have been largely left on the sidelines.

New data this week from the Federal Reserve shows that in the first quarter of this year, U.S. businesses were taking on new debt at the fastest rate since the financial crisis in 2008. U.S. households, though, were heading in the opposite direction, increasingly shedding debt.

And as in the case of Shreve, the lack of borrowing by U.S. families was not always by choice. Another recent Fed report shows that while more consumers are interested in buying homes or refinancing existing mortgages, banks remain hesitant to extend credit to them.

Consumers are also getting squeezed on the investing front. Wary of the volatile financial markets and worried about the continued weakness in the economy, they have been putting more money into ordinary savings accounts, the new data shows. But those accounts are paying an average of 0.1 percent, according to Bankrate.com.

“There’s definitely winners and losers in this kind of extremely low interest rate environment,” said Ed Yardeni, the president of Yardeni Research. “In this case, any borrower that has access to the capital markets and doesn’t have to fill out a loan application at a bank is definitely going to have a tremendous advantage.”

Of course, the declining debt load of households is not necessarily bad. Many economists see it as a welcome shift from the borrowing binge that helped cause the financial crisis, and the Fed data shows that the lack of new debt has freed consumers up to spend more.

“What Americans have learned is that they can live with the old house,” said Allen Sinai, the chief executive of Decision Economics. “Why take on debt and obligate yourself? They are unencumbered more than ever before.”

But the new data underscores the polarizing impact of the central bank’s policy of pushing down interest rates on different segments of the U.S. economy. While low rates are supposed to encourage Americans to take more risks, ordinary Americans have been unwilling or unable to take advantage of them.

Cautious spending

Not all types of consumer debt are in decline. As education costs rise, the amount of outstanding student loans rose in each of the first five months of the year, Equifax data analyzed by Moody’s Analytics showed. Lending to buy cars has also been heading upward, though with a distinct note of caution.

Alan Starling, who owns three car dealerships in the Orlando, Fla., area, said he had watched consumer behavior evolve over the last several years. “Cautious,” he said. “That is the word.”

Consumers coming to Starling are asking more questions about the fuel efficiency of the cars and worrying more about the monthly payments, he said.

“People are much more conscious of debt and not getting yourself overextended,” Starling said. He added that he drove a Chevy Volt and spent only about $25 a month on gas.

The biggest category of household debt by far is residential real estate, and debt in that sector has continued to drop for several reasons. Foreclosures and defaults have erased some of the obligations, and prospective home buyers are being held back, in part, by the restraint of the banks. A Fed survey of senior loan officers at U.S. banks in April indicated that most banks had kept lending standards the same, or tightened them somewhat, even with a steady or rising demand for mortgages. About two-thirds of mortgage activity has been for refinancing existing loans, not for new mortgages, according to Guy Cecala, publisher of Inside Mortgage Finance.

“The real problem is that relatively few borrowers meet the tougher standards of today even if they could benefit from refinancing, and that is the frustration,” said Cecala.

He added that the last time there was more normal underwriting, in 2003, there was nearly $4 trillion in total mortgage originations, which includes refinancing and new purchases. Last year, with tougher underwriting and lower rates, total originations were $1.4 trillion.

In general, though, consumers’ anxiety about taking on new risks is driving many household decisions.

Joseph Butler, a retired banker in Bernice, La., said that after seeing the trouble that debt caused during the financial crisis, taking on loans or any other kind of risk seemed foolish. Butler said he was now entirely out of financial investments and kept all his money in a savings account at his local bank, earning less than 1 percent a year.

“I want to hunker down on what I’ve got,” he said.