{"id":1294,"slug":"zillow-zestimate-error-rates","title":"Zillow Zestimate published error rates — ~1.9% on-market, ~7.5% off-market; lawsuits; 7th Circuit 2019 sided with Zillow partly because \"estimate\" was clearly labelled","kind":"reference","scope":"business","status":"current","audiences":["kevin","smb-owner","candid-team"],"topics":["open-data","data-infrastructure","accuracy-risk-published-data"],"reference_body":"**Claim:** Zillow's **Zestimate** has a published national median error rate of **~1.9% (on-market)** and **~7.5% (off-market)** — meaning half of off-market estimates are off by **more than 7.5%**, and in some metros (e.g., Pittsburgh **~11.3%**) materially higher.\n\nZillow has faced lawsuits alleging the Zestimate misled buyers/sellers; courts sided with Zillow (**7th Circuit, 2019**), partly because it labels the figure an **estimate**, not an appraisal.\n\n**Source:** Houwzer (citing Zillow methodology); GeekWire (7th Circuit case).\n\n**Confidence:** Verified.\n\n**Why this matters for Candid:** Worked example for **how labelling protects you**. The legal defence rested on honest framing — see [[rule-label-every-published-data-figure-with-vintage]]. Companion to the calculator brief: same principle in the customer-facing-calculators world, see [[rule-label-every-estimate-with-vintage]].","rationale_body":null,"metadata":null,"links":{"outgoing":[{"slug":"anchoring-effect-tversky-kahneman-1974","title":"Anchoring effect (Tversky & Kahneman, 1974) — the first number presented becomes a reference point that pulls all later judgments, even when arbitrary","kind":"reference","scope":"business","link_type":"relates-to"}],"incoming":[{"slug":"research-brief-data-driven-tools-smb-june-2026","title":"Research brief: live data and data-driven tools for SMBs — when it's an edge, when it's overkill (June 2026)","kind":"reference","scope":"business","link_type":"relates-to"},{"slug":"rule-label-every-published-data-figure-with-vintage","title":"R6 — Every published number gets a label (what it is) and a vintage (how fresh); the Zestimate defence depends on it","kind":"rule","scope":"business","link_type":"depends-on"}]},"created_at":"2026-06-20T16:57:38.964Z","updated_at":"2026-06-20T16:57:38.964Z"}