Redfin’s 6-12% inventory boost claim rests on unstated assumptions, not data

A report claiming pre-marketing could boost home inventory by 6-12% relies on behavioral assumptions with no supporting data, according to Zillow’s chief economist. Redfin’s analysis assumes half of sellers would decide to list publicly after testing pricing in a pre-market phase, but offers no evidence that sellers actually respond this way. The estimate is built by multiplying assumed shares of uncertain sellers, those who would act on early feedback, and a multiplier for chained transactions—none of which are grounded in observed U.S. market behavior. Some inputs cite a study of Dutch homeowners in the 1990s and tax effects in 2010s Toronto, raising questions about relevance to today’s American sellers. Redfin referenced Zillow surveys suggesting pricing hesitation, but Zillow says those surveys identified broader constraints like affordability and life uncertainty—factors the report downplayed. The model also ignores sellers who exit the market after unsuccessful pre-marketing, a withdrawal that reduces net inventory. Zillow’s Mischa Fisher calls the result a “stack” of unverified fractions, not a data-driven projection. Redfin defends its work, stating all assumptions are公开 and the model allows for alternative inputs—even halving the key elasticity still yields a 3-6% inventory increase. The company says it welcomes scrutiny and will continue researching the topic.