Washington ? With their interest rate decision today, Chairman Ben Bernanke and his colleagues at the Federal Reserve will convey just how worried they are that banks and other financial institutions are putting the economy at risk by hoarding cash.

The Fed’s policymaking committee will decide whether to lower a short-term interest rate for the third time this year. Based on prices in futures markets Monday, investors believed that there is a 68 percent chance that the Fed will cut the federal funds rate by a quarter of a percentage point, a 30 percent chance of a half-point cut and a 2 percent chance that the Fed will leave the rate at 4.5 percent.

The decision could hinge on arcane indicators that capture the degree to which banks are afraid to loan money to each other, in addition to the usual grist for economic prognostication, such as the employment outlook and inflation expectations.

The more worried the Fed is about lenders becoming unwilling to make loans, the more likely it is to cut by half a percentage point to stimulate the economy and allay fears of a crisis.

The meeting will be the latest example of the government trying to grapple with the housing and credit crises that began this summer. Today, Senate Banking Committee Chairman Chris Dodd, D-Conn., plans to introduce legislation meant to give the Fed and other bank regulators new authority to try to keep such problems from happening again.

The economy is increasingly threatened not merely by a steep downturn in housing, economists say and Fed leaders have acknowledged in recent speeches. They also worry that financial institutions that would normally lend money to consumers and businesses and help keep the economy growing are becoming fearful of massive losses from bad loans.

Instead of making the situation better, they could make it worse by offering loans only at higher cost – something that happened in November.

“Bankers and other lenders are becoming more cautious and more choosy in who they lend to,” said Bruce McCain, of Key Private Bank. “Every person or borrower who is priced out of the market or refused a loan is that much less stimulus to the economy.”