WASHINGTON — Federal Reserve Chairman Ben Bernanke has made clear he'll go to the mat to knock down inflation, increasing the likelihood that interest rates will rise again at the end of the Fed's two-day meeting tomorrow.

Other Fed chiefs have sought early in their tenures to show their inflation-fighting resolve. Here are some questions and answers about why they believe inflation is such a threat.

Q. Why is the Federal Reserve concerned?

A. Once inflation gets a grip on the economy, it can be hard to break. A rapid rise in prices erodes the purchasing power of consumers. It can squeeze companies' profits, too, and that can make employers reluctant to hire workers and increase capital spending. It can diminish returns on investments. If consumers and companies clamp down on spending in response to rising prices and interest rates, the economy can be thrown into a recession.

Q. What exactly is inflation?

A. A rise in the prices of goods and services. In economist-speak, inflation occurs when too much money is chasing too few goods.

Q. How does the Fed treat inflation?

A. The Federal Reserve raises interest rates. Those higher rates make it more expensive for consumers and businesses to borrow. That can curb their appetite to spend, which in turn can moderate economic growth and that can lessen inflation pressures.

The goal for Bernanke and his colleagues is to push up rates enough to quell inflation but not too much as to tip the economy into recession. It's a tricky task.

Bernanke's predecessor, Alan Greenspan, engineered such a "safe landing" for the economy after the Fed's rate-raising campaign from 1994 to early 1995 that some say helped usher in a record-long economic expansion. But the Greenspan Fed, following two other rate-raising cycles, also saw the economy tip into recession — once in 1990 and again in 2001.

Q. What are current barometers saying about inflation?

A: Although inflation is picking up, the situation is not even close to approaching the double-digit inflation dangers of the '70s and early '80s. Consumer prices for the first five months of this year raced ahead at an annual rate of 5.2 percent — outpacing the 3.4 percent rise for all of 2005.

Core prices, which exclude food and energy, are advancing at a 3.1 percent pace so far this year. That compares with a 2.2 percent increase in 2005. Fed policymakers pay close attention to measures of core inflation.

Q. If inflation takes off, what does it mean for me and my pocketbook?

A. You'll be paying more for goods and services. Inflation also can eat into investment returns.