This report provides a monthly analysis of housing inventory levels by price range for detached properties in several Chicago suburbs for November 2009, December 2009, and January 2010. It shows the number of active listings, average days on market, and months of supply for different price tiers in communities such as Addison, Algonquin, Arlington Heights, Aurora, and others. Overall, inventory levels decreased slightly from November to January while average days on market and months of supply generally remained stable or increased slightly.