LOW RATES: Average U.S. rates on fixed mortgages declined this week and remained near historic lows, a trend that has buttressed a recovery in housing.

THE NUMBERS: The average rate on the 30-year fixed mortgage fell to 3.54 percent from 3.63 percent last week. That's near the 3.31 percent reached in November, which was the lowest on records dating to 1971. The average on the 15-year loan slipped to 2.72 percent from 2.79 percent.

ECONOMY BOOST: The lowest mortgage rates in decades are spurring more home purchases and refinancing. That's helped the broader economy. Increased sales also are pushing home prices higher.