Inventory levels in 2012 reached an 11-year low and fell yet again last month, further limiting the number of homes for sale nationwide. Inventories of for-sale homes were down by 16.5 percent in January year-over-year, and fell 5.6 percent from December, according to the latest data compiled from Realtor.com.

Inventories typically fall in December and January in preparation of the spring buying season.

“But the shortage of homes for sale in a growing number of U.S. markets is maddening for would-be buyers who frequently complain that there aren’t enough good choices,” The Wall Street Journal reports. “Bidding wars are becoming more common.”

At a time when buyer demand is strong, inventories remain constrained as banks slow their pace of foreclosures and home owners delay selling until they regain more equity in their homes.

Metro areas posting some of the largest monthly declines in inventory levels are San Francisco (where inventory levels are down by 21 percent in January compared to December and down 47 percent year-over-year) as well as Seattle (where levels dropped 9 percent from December). The two have also seen some of the largest price increases in the nation. Median asking prices have risen by 16.4 percent and 23.7 percent in those places, respectively.

Source: “Housing Inventory, Already Low, Dropped Further in January,” The Wall Street Journal