Data Methodology for the First-Time Homebuyer Tax Credit press release.

The complete press release can be found here.

1. Harris Interactive® fielded the Tax Credit study on behalf of Zillow from Aug. 28 – Sept. 1, 2009 via its QuickQuerySM online omnibus service, interviewing a nationwide sample of 2,175 U.S. adults aged 18 years and older, of whom 408 do not currently own a home as their primary residence and have not owned a home as their primary residence for the past three years, and who intend to buy a home before the end of 2010. . This online survey is not based on a probability sample and therefore no estimate of theoretical sampling error can be calculated. For complete survey methodology, including weighting variables, please contact press@zillow.com.

2. Zillow estimates that 1.86 million first-time homebuyers could receive the tax credit if it were extended for an additional 12 months (from Dec. 1, 2009 to Nov. 30, 2010 – the likely time frame for the extension). Zillow analysis determined that 4,319,100 homes will likely be sold during the 12 months leading up to Nov. 30, 2009). Based on data from the National Association of Realtors, Zillow conservatively estimates that home sales will rise 5 percent in 2010 compared to 2009. That would mean that 5,158,755 homes would sell between Dec. 1, 2009 and Nov. 30, 2010 – the probable life of an extended tax credit.

According to NAR, 36 percent of all homebuyers who purchased their home between March 2009 (the first full month after the credit was announced) and July 2009 were first-time homebuyers. Assuming 36 percent of all buyers would be first-time homebuyers during the life of an extended credit, 1.86 million who buy between Dec. 1, 2009 and Nov. 30, 2010 would be first-time homebuyers. 

3. If 1.86 million homes are sold to first-time homebuyers who qualify for the full $8,000 tax credit between Dec. 1, 2009 and Nov. 30, 2010, the total amount of credits given would be $14.86 billion.