Zillow reported today that the greatest year-over-year decreases in inventory have been among more expensive homes, with the availability of top-tier and middle-tier properties each falling 15.7 percent year-over-year. The number of bottom-tier properties for sale on Zillow nationwide fell only 2.5 percent in early June compared to June 2012.

The analysis counters the conventional belief that supplies of lower tier homes have declined more than higher priced homes due to the effects of negative equity, which is more prevalent among mid and lower income homeowners, and declining numbers of distress sales, which are generally lower priced homes.

Other sources show that it is taking two or three times longer to sell higher priced homes than the average priced home. The Institute for Luxury Home Marketing reported Tuesday that the average days on market for homes priced over $500,000 was 161 in the first week of June. The National Association of Realtors reported the median time on market for all homes was 46 days in April, down sharply from 62 days in March, and is 45 percent faster than the 83 days on market in April 2012. The median age of inventory for all homes on Realtor.com was 79 days in May.

Zillow: Luxury Homes Lead Inventory Declines | RealEstateEconomyWatch.com.