Rock-bottom interest rates and stronger sales in higher-priced neighborhoods helped Southern California's housing market post robust gains in the typically sleepy month of December, new data show, and experts say the momentum is continuing -- ushering in an early start to the spring home-buying season.

The median price paid for a Southland home rose 4% to $289,000 last month from December 2008, the first time the closely watched figure has posted a year-over-year gain since the region's real estate market took a nose dive 2 1/2 years ago, according to data released Tuesday by MDA DataQuick, a San Diego real estate research firm.

Rebounding home prices could help the Southern California economy recover from its slump, as a stronger housing market could lead to hiring on construction sites and in real estate sales, title and escrow offices, said Esmael Adibi, director of Chapman University's A. Gary Anderson Center for Economic Research.

"The worst is behind us for sure," he said. "For the economy, the implication is, at least on the residential side, we don't expect more layoffs, and you might actually see some pickup in employment."