This excerpt taken from the ALL 10-Q filed Nov 6, 2008.
ABS residential mortgagebacked securities (ABS RMBS); Alt-A residential mortgagebacked securities (Alt-A): ABS RMBS and Alt-A are principally valued based on inputs including quoted prices for identical or similar assets in markets that exhibit less liquidity relative to those markets supporting Level 2 fair value measurements. Certain ABS RMBS and Alt-A are valued based on nonbinding broker quotes. Due to the reduced availability of
THE ALLSTATE CORPORATION AND SUBSIDIARIES
NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS
actual market prices or relevant observable inputs as a result of the decrease in liquidity that has been experienced in the market for these securities, all ABS RMBS and Alt-A are categorized as Level 3.