Two real estate giants are deciding which homes you’re allowed to see

On Sept. 15, federal Judge John Tharp in Chicago handed down a ruling that will shape what homes American buyers can find online. Almost no one outside the industry noticed.Tharp denied Zillow’s request to block Midwest Real Estate Data (MRED) from enforcing its listing rules, dissolved an earlier restoration of Zillow’s access to Chicago-area listings, sent Zillow’s claims against the MLS to arbitration, and stayed the related case against the brokerage firm, Compass. That means a dispute over who controls access to listings in the country’s third-largest metropolitan market is now headed into private arbitration.Buyers and sellers in the area are not parties to that proceeding, but they will need to live with its result. The issue itself sounds like a minor squabble. But it could reshape the housing market as we know it. Compass finalized its acquisition of Anywhere Real Estate in January, which owns other real estate firms, and has built its strategy partly around “private exclusives,” listings marketed within the brokerage before reaching the open market. It now represents roughly a third of transaction sides in some markets.In March, Zillow launched Zillow Preview, a premarket listing product whose launch partners collectively account for roughly 30% of the residential brokerage market. Those listings appear on Zillow, Trulia, and through a separate agreement with Realtor.com. They do not appear on Homes.com, Redfin, or the traditional MLS.That is functionally the same practice Zillow condemns when Compass does it. Only here, the exclusive window runs to Zillow’s benefit instead.So the argument in Chicago is not whether listings should be restricted, but about which firm gets to restrict access and get away with it. This is precisely where antitrust enforcement should be a priority.The FTC just settled a case built on the principle that a dominant platform may not neutralize a rival in listing distribution. In this particular case, exclusivity in the rental market was purchased for $100 million, while the housing listing exclusivity is secured through preferential access.This isn’t the only issue with Zillow’s strengthening control. Less than two years after litigation dismantled the National Association of Realtors’ commission structure, Zillow is paying listing agents 10% of the buy-side commission when a Zillow Preview listing closes through the company’s Preferred Agent network, functionally re-establishing a nationwide commission agreement that was just dismantled. And Zillow Home Loans is now the 25th-largest mortgage lender in the country, with pending class actions alleging that the company steers buyers toward its own, more expensive products. Congress has begun to notice. The House Judiciary antitrust subcommittee, chaired by Rep. Scott Fitzgerald (R-WI), sent letters to Compass and MRED in July seeking briefings on private listing networks and their effects on consumers. A coalition of consumer, housing, and civil rights groups has urged the FTC and Justice Department to investigate the Compass-MRED partnership.ZILLOW TRAPS BUYERS INTO OVERPRICED MORTGAGES, AND IT’S COSTING AMERICANS $65 BILLION ANNUALLYThese are good starts. But the FTC should also open a market study covering online residential search and listing distribution and our antitrust enforcers to seriously investigate exclusive premarket access and platform-set commission payments before they become an industry default.A home is the largest purchase most families ever make, and the foundation of whatever wealth they pass on. The rules governing which buyers learn that a house is for sale, which agents they are handed to, and which lender finances the purchase should not be settled in a private arbitration between two companies that both profit from the answer.Anthony Constantini is a policy analyst at the Bull Moose Institute.