America’s accidental landlords: The hidden consequence of the mortgage lock-in effect

For the past several years, the real estate industry has talked about the mortgage-rate lock-in effect mostly as an inventory problem. That is understandable. When a homeowner has a 3% or 4% mortgage, and today’s replacement mortgage is in the mid-6% range, selling can feel financially irrational. Freddie Mac reported that the 30-year fixed-rate mortgage averaged 6.43% as of July 2, 2026. Realtor.com, using data from the FHFA National Mortgage Database, found that just over half of outstanding mortgages still carried rates of 4% or lower as of the fourth quarter of 2025. FHFA researchers have also found that for every percentage point the market mortgage rate rises above a homeowner’s origination rate, the probability of sale falls by 18.1%. Their working paper estimated that lock-in prevented 1.33 million home sales from 2022 Q2 through 2023 Q4. But there is another consequence we do not talk about enough. Homeowners are moving, even when they are not selling When homeowners cannot make the math work to sell, many do not simply stay put. Life keeps moving. People accept new jobs. Military families receive orders. Families grow, parents age, marriages change and homeowners relocate...