The Private Listing Studies

What They Say, What They Leave Out, and What an Agent Must Disclose

July 29, 2026

Why This Matters Now

Two of the largest companies in residential real estate are running studies about the same question and getting opposite answers. The question is simple. Does a home sell for more when it is marketed privately first, or when it goes straight to the MLS and the public portals?

The answer is being used every day in listing presentations. That makes it a fiduciary matter, not just a marketing one. An agent who quotes a number to a seller is giving advice. If that number pushes the seller toward a choice that also happens to benefit the brokerage, the duty to explain the whole picture becomes stronger, not weaker.

This paper reviews the main studies in plain language. Each study is linked where it is discussed, so any figure can be checked at the source. The paper closes with what an agent should disclose before using any of these numbers with a client.

The New Compass Study

On July 29, 2026, Compass released a study it calls The Zillow Tax. The study says homes that appear on Zillow sell for 1.3 percent less than homes that do not. On a $430,000 home, that is about $5,590. HousingWire covered the release the same day.

The headline says the study looked at more than 300,000 homes. That is true, but it hides something. Compass reviewed 296,966 listings from January 2025 to May 2026. Only 806 of those were actually banned from Zillow. The group being tested is 806 homes. That is about one quarter of one percent of the total. The other 296,000 are only the comparison group.

There is a bigger problem. The study is not really comparing homes on Zillow to homes off Zillow. It is comparing homes that broke Zillow display rules to homes that did not. A home gets banned from Zillow when it is publicly advertised somewhere else first. So the banned group is made up mostly of the listings that used the Compass phased marketing plan the hardest. Compass says it adjusted for that. But when the thing being tested and the thing being controlled for are nearly the same thing, adjusting for it does not accomplish much.

The Measuring Stick Is the Real Issue

This is the part that matters most. Compass measured the sale to list ratio. That is the final sale price divided by the asking price. A home that lists at $500,000 and sells at $500,000 has a ratio of 100 percent.

Every other serious study in this fight measured something different. They compared the sale price to an outside estimate of value. Zillow started with the Zestimate from three months before the sale, adjusted it for how prices moved in that ZIP code, and then compared the actual sale price to that number. Bright MLS used a statistical model built from the features of the home. Professor Darren Hayunga matched each private sale to nearly identical public listings. Compass used the asking price the seller set.

That single choice probably explains the whole result. The entire point of private premarketing is to test the price before going public. A seller who spends weeks quietly collecting feedback, and who in some cases already has a buyer waiting, will pick an asking price that is going to be met. A ratio of 100 percent is what happens when a seller lists at a number already known to work.

That is a real service. It is not proof of a higher price. It is proof of a better guess. Compass is measuring how well the seller guessed and calling it how much the seller made.

Three Smaller Problems

The study blames days on market, price cut history, and the Zestimate for pushing prices down. Two of those three come from the MLS, not from Zillow. Zillow only displays them.

The study points to 80 Clarkson Street, a new condominium building that sold more than $1 billion in contracts without ever appearing on Zillow. New construction is a different animal. Zillow specifically removed new construction, foreclosures, auctions, and family transfers from its own study because those sales do not work like ordinary home sales. Using a new condominium tower to prove a point about ordinary sellers does not hold up.

Then there is timing. Compass announced in March 2026 that Zillow had agreed to stop banning sellers for publicly marketing on Compass or Redfin sites first, and Compass dropped its lawsuit for that reason. If the rules changed partway through the study window, then the 806 banned homes are drawn from a shorter period than the 296,000 comparison homes. That is worth asking about.

The Studies That Point the Other Way

Zillow, May 2026

Zillow looked at more than 15 million sales from 2023 to 2025. Sellers who stayed off the MLS sold for about 1.3 percent less, roughly $4,230 per home, or $1.36 billion in total. Sellers of lower priced homes lost about 2.2 percent. The pattern appeared in all three years. Zillow published earlier research along the same lines in February 2025.

Notice the coincidence. Zillow says staying off the MLS costs 1.3 percent. Compass says being on Zillow costs 1.3 percent. Same size, opposite direction. That is unlikely to be an accident. Compass chose a frame that cancels out the number most often used against it.

Lawrence Wu, Economist Retained by Zillow

In court filings, Wu found that Compass private network sales went for about 4 percent less in the Chicago area and 4.8 percent less nationally. He identified those sales as homes that entered the MLS already sold, with Compass agents on both sides. That means his group is largely deals where one brokerage collected both commissions. His study mixes the private listing effect together with the double commission effect. The same criticism that weakens the Compass design weakens this one.

Bright MLS, April 2025

This study gets the least attention and deserves the most. Bright reviewed about 100,000 sales. Standard listings went under contract in a median of 20 days. Listings that started as office exclusives took 37 days. Nearly nine out of ten homes that started private ended up on the MLS anyway. There was no price advantage. The design is stronger because it compares private listings to normal listings inside the same market, rather than to a grab bag of unusual sales.

Bright MLS and Drexel University, 2023 and 2024

This study found homes on the MLS sold for 17.5 percent more. That number should be retired. The off MLS comparison group includes for sale by owner, family transfers, and distressed sales. Those homes sell for less for reasons that have nothing to do with the MLS. Bright later found no meaningful price difference, which is the more defensible finding.

The Studies That Agree With Compass

Professor Darren Hayunga, University of Georgia

Hayunga studied about 700,000 sales in the Dallas-Fort Worth area from 2002 to 2022. He found private sales brought 1.7 percent more, and concluded the reason was avoiding the price haggling that comes with public listings. For the most expensive one percent of homes, the gain was about 8 percent.

Compass quotes this study. Compass leaves out the most important part. After May 2020, the advantage falls to about 0.9 percent and is no longer statistically meaningful. May 2020 is when Clear Cooperation took effect. In plain terms, the advantage existed before the rule and mostly disappeared after it. That is the finding that matters most for the policy debate, and it is the one the Compass release does not mention.

The Earlier Compass Studies

Compass reported a 2.9 percent price gain using 2024 data, then 4.6 percent using data from April 2025 through March 2026, along with a claim of selling 34 percent faster. That study counted only homes that actually sold. It did not report how many listings expired or were withdrawn, how long homes sat in the private phase, or whether they took price cuts during it. When a measured effect grows by more than half in a single year with no change in the underlying method, the likelier explanation is a change in how it was measured, not a real improvement.

What Is Probably Really Happening

Both sides may be right, just about different homes.

Private marketing probably does help when a home is unusual, expensive, and hard to price, and when the likely buyers are few and reachable through agents. Broad public exposure probably does help when the home is ordinary and there are many possible buyers, because competition is what drives the price up.

Look at the two findings together. Hayunga found an 8 percent gain at the very top of the market. Zillow found a 2.2 percent loss at the bottom. Those are the same pattern seen from opposite ends. Neither company will say this out loud, because neither one gains from saying it. And an average calculated across a group where the effect changes direction is close to useless.

The price argument is also a cover story. Zillow makes money selling buyer leads. Compass makes money holding inventory that attracts agents. Whoever controls where buyers begin their search wins. The studies are the public face of a fight over distribution.

Here is what should concern MLS leaders. Compass is aiming at Zillow, but the shots land on the MLS. Days on market and price cut history are MLS fields, entered by MLS participants under MLS rules, and sent out through IDX. If the industry accepts the idea that those fields destroy seller value, the natural next step is not to leave the portal. It is to leave the MLS, or to make the MLS stop publishing the field.

There is a fair version of that complaint. Days on market is defined differently across MLSs. The reset rules get gamed. Price history display varies. If those fields are the strongest honest argument for going private, then standardizing and rationalizing them does more good than any counter study. Better to fix the field than to defend it.

Where This Ends

It does not end with more studies. Nobody is going to be persuaded by the other side of a lawsuit.

It ends with a court, a regulator, a state legislature, or genuinely independent research. The last one is the only path the industry controls, and it is the one nobody has taken. What is needed is a study across many markets, using MLS level transaction data, run by an outside party, with the method published before anyone sees the results. Every number in this debate today either comes from a company that is suing someone, or from a single market working paper whose central finding disappears after 2020. A side by side comparison of the competing findings makes the pattern plain. An industry funded, preregistered, third party study would be worth more than everything both sides have published combined. It would also be awkward for either side to refuse to join, which is part of its value.

What an Agent Must Disclose

An agent owes a client fiduciary duty. That means putting the interests of the client ahead of the interests of the agent and the brokerage. Informed consent means the seller understands the real choice, including the parts that are not flattering. Using a statistic in a listing presentation is not marketing. It is advice. What follows should be said out loud and put in writing.

Say who paid for the study. The Compass studies were performed by Compass employees, about Compass listings, while Compass was in court against Zillow. The Zillow studies were performed by Zillow employees while Zillow was in court against Compass. Neither is independent. Neither is peer reviewed. A seller has a right to know that before deciding anything.

Say what was actually measured. If the 1.3 percent Zillow Tax figure is used, explain that it compares the sale price to the asking price, not to an outside estimate of value. If the 4.6 percent premium is used, explain that it counted only homes that sold, and did not report how many did not.

Say how large the tested group really was. Eight hundred and six homes is the treatment group in the Zillow Tax study. The 300,000 figure describes the comparison pool.

Give the whole finding, not the half that helps. An agent who cites the Hayunga 1.7 percent premium must also say that the advantage falls to about 0.9 percent after 2020 and is no longer statistically meaningful. Quoting the first half without the second half is not a rounding error. It leaves out the part that would change the mind of the seller.

Name the studies that point the other way. An agent using Compass numbers should mention the Zillow and Bright MLS findings. An agent using Zillow numbers should mention Hayunga. A seller cannot give informed consent to a one sided briefing.

Say that averages do not predict this house. These studies report averages across tens of thousands of homes in many markets and many price ranges. They do not tell a seller what will happen to this home, on this street, at this price, in this month.

Disclose the financial interest of the agent and the brokerage. A brokerage that operates a private network benefits from holding inventory in it whether or not the seller benefits. If there is any real chance the buyer will come from inside the same brokerage, or from the same agent, say so, and explain what that means for who is negotiating on behalf of the seller. This is the disclosure most often skipped and the one most likely to be examined later.

Disclose the tradeoffs plainly. Fewer buyers will see the home. Bright MLS data shows private listings took a median of 37 days to go under contract compared with 20 days for standard listings, and nearly nine out of ten reached the MLS in the end anyway. A seller should understand that the private phase may simply delay the public listing rather than replace it.

Disclose the fair housing dimension. Limiting who sees a home limits who can buy it. Regulators and consumer groups have raised this directly. It is a real risk to the seller, to the agent, and to the brokerage.

Confirm that the seller knows they can say no. Going straight to the MLS is a legitimate choice and must be presented as an equal option, not as the fallback after the pitch.

Put it in writing. Written seller consent for off MLS marketing is required under MLS rules and, increasingly, under state law. Beyond that, record what was disclosed and when. If this is ever reviewed, the file is the defense.

A Simple Test

If the seller later read every study the agent quoted, in full, would that seller feel fairly represented, or would that seller feel handled? If the honest answer is the second one, the presentation needs to change.

One caution. Disclosure requirements vary by state and by MLS. Any disclosure form or listing presentation script built from this paper should be reviewed by brokerage counsel and checked against local MLS rules and state agency law.

Where to Read the Studies

The links in this paper are live in the electronic version. The full addresses are printed below so that a paper copy remains usable. An agent who intends to quote any figure in a listing presentation should read the underlying study rather than the coverage of it.

Compass International Holdings

The Zillow Tax, July 29, 2026.  https://www.compass.com/newsroom/research/1eTHuNQPPguM2fnzE7X6M3/

Three Phased Marketing Strategy research page, including the 2.9 percent finding and its stated confidence interval.  https://www.compass-homeowners.com/

Compass to Dismiss Lawsuit Following Zillow Ban Reversal, March 18, 2026.  https://www.stocktitan.net/news/COMP/compass-to-dismiss-lawsuit-following-zillow-ban-ny8nl0aoxi0d.html

Coverage of the 4.6 percent finding by RISMedia.  https://www.rismedia.com/2026/07/24/compass-releases-study-private-listings-larger-premium/

Coverage of the 4.6 percent finding by Real Estate News, with the stated limits.  https://www.realestatenews.com/2026/07/24/compass-says-phased-marketing-delivers-4-6-sale-price-premium

Coverage of the competing Compass and Zillow figures by Inman.  https://www.inman.com/2026/07/24/compass-zillow-private-exclusives-data-research-listings/

Coverage of the Zillow Tax release by HousingWire.  https://www.housingwire.com/articles/compass-zillow-tax/

Zillow Group

Dual agency and off MLS study, May 14, 2026, with methodology.  https://investors.zillowgroup.com/news-and-events/news/news-details/2026/Selling-with-one-agent-on-both-sides-cost-home-sellers-1-49-billion-over-three-years/default.aspx

Coverage of the same study by Real Estate News.  https://www.realestatenews.com/2026/05/14/sellers-lose-over-2k-on-typical-dual-agency-transaction-study

Earlier Zillow research on private listing networks, February 2025.  https://www.zillowgroup.com/news/private-listing-networks-are-damaging-the-housing-market/

Reporting of the Lawrence Wu court figures, Housing Notes, July 27, 2026.  https://housingnotes.com/p/compass-employees-made-their-own

Bright MLS

Office exclusives research by Lisa Sturtevant, 2025, full report.  https://www.southernmarylandrealtors.org/clientuploads/Bright_MLS/BrightResearch_office_exclusives.pdf

Coverage of that report by Inman.  https://www.inman.com/2025/04/04/private-listings-offer-no-clear-advantage-for-sellers-bright-mls/

On MLS and off MLS study with Drexel University, full report.  https://assets.ctfassets.net/1g8q1frp41ix/69PEVCSSUVfYRCqrSpKKEd/35da1493a4976e721947ccbbbe4c44d8/Bright_MLS_On-Off_MLS_Study.pdf

Commentary citing the Drexel figure, HousingWire, June 3, 2026.  https://www.housingwire.com/articles/compass-zillow-mls-listing-access/

Academic and Independent

Darren Hayunga, Pocket Sales in the Housing Market: Selection, Outcomes, and Policy, University of Georgia working paper.  https://papers.ssrn.com/sol3/papers.cfm?abstract_id=6359754

Analysis of the Hayunga findings after 2020, HousingWire, April 7, 2026.  https://www.housingwire.com/articles/private-listings-premium-fades/

Wharton School research on portal contact routing, cited by Compass in the Zillow Tax release.  https://papers.ssrn.com/sol3/papers.cfm?abstract_id=6140990

TRH Consulting side by side comparison of the Compass, Bright MLS, and Zillow findings.  https://www.teresahowe.com/blog/facts-dont-lie-or-do-they

Links were verified on July 29, 2026. Some publications place articles behind a subscription wall.

Copyright 2026 Saul Klein. All rights reserved.