"Conceptual limitations in estimates of unsold inventories of both new and existing homes have encouraged us to focus on Census Bureau estimates of vacant year-round homes for sale that are produced on a quarterly basis. These estimates include unsold completed new homes in the hands of builders along with vacant existing ― previously owned ― homes for sale.
"There were nearly 5.8 million year-round housing units on the market at mid-2007, down from a record 6.1 million three months earlier but higher than any previous number on record. Both the for-sale and for-rent components of this total were down from their first-quarter records, but both remained historically high.
"The for-sale measure remained in the stratosphere at mid-2007, reflecting massive increases recorded in both single-family and multifamily (condo) markets since mid-2005. Total for-sale vacancies were 2.0 million at mid-2007, about four-fifths of these (1.6 million) were single-family homes, and nearly nine-tenths of single-family vacancies were in the existing-home market — a legacy of the investor/speculator buying binge during the boom years. "