The U.S. is riding the greatest housing price explosion since the height of the 2006 craze, setting a pace that's due to hit the mid-teens by early spring, according to the American Enterprise Institute's Housing Center. But this boom is a game changer, a completely different phenomenon from previous bull runs featuring super-low mortgage rates and slender inventories. In a historic turnabout that's one of the biggest, most underreported stories of the COVID economy, expensive homes—which almost always lag in a surging market—are racing neck-and-neck with the sizzling low end.

The reason: Affluent Americans who used to shop for move-up manses where they live and work no longer need to commute to an office complex and can work from anywhere. So they're selling in San Jose, Seattle, or Chicago and buying a bigger, cheaper house in Phoenix or Boise or Cincinnati, where they Zoom with colleagues from expansive home dens, spend weekends poolside, and watch their kids frolic in a big backyard.

"This trend was already underway, but the pandemic made it far stronger," says Ed Pinto, director of the AEI Housing Center. "We've never seen a housing arbitrage play on anything like this scale, with people seeking better deals in far-flung cities regardless of where they work. It reminds me of the great land rush of the mid-1800s where as land got more expensive in Illinois, people went to Kansas for bigger, cheaper farms, then kept moving west for more space and better deals. It's the free market winning in housing."

In past strong markets sustained by low rates, it has been the least expensive homes that almost always showed the fastest gains. The upper tiers benefited, too, but less so. The affluent customers living and working in, say, San Jose, were most often shopping for a move-up home in San Jose.

Those families were typically putting up more cash and using less leverage than first time buyers supported by the Federal Housing Administration (FHA), says Pinto. "They were a more conservative group. They could buy more house with the same monthly payment as before, and often did," he adds. "But a family living in a nice three-bedroom, $1 million house still liked that house. They didn't necessarily sprint to buy the more expensive four-bedroom house across town.”

It wasn't like the low end, where the government is providing so much help it's really telling you, “Go buy that house!” The upshot is that in good times, the FHA crowd purchasing their first homes tended to pump the accelerator at the low end a lot harder than the high-earners shopping in their hometowns did for the colonials and postmoderns in the upper range.

Mobile homes

Americans’ newfound mobility is reversing that longstanding trend. Since June, expensive homes pulled even with the low end in October, and have been keeping pace ever since. The AEI splits homes into four price buckets: low, low-medium, medium-high, and high, and provides the breakdowns for 40 metros. Sales at or below the 40th percentile for those financed with FHA loans fall in the low bin. That numbers ranges all over depending on the metro; in San Diego, the average in the low bin is $377,000, while in Charlotte it's $147,000. The "medium-high" sits at $681,000 in Seattle and $414,000 in Phoenix. High-end abodes are usually too expensive for FHA, Fannie Mae, or Freddie Mac financing, so buyers typically get lower home-to-value mortgages in the 70% to 80% range from banks or other lenders.

From 2012 to mid-2020, "low" far outperformed the higher ranges, booking average appreciation of around 7% a year, versus roughly 5% for "medium-high" and 4% for "high." A year ago, low still enjoyed a significant lead in both categories. But the numbers for January show all three tiers locked in a tight race, and speeding at rates not witnessed in a decade: the low end sprinting at 14.3%, medium-high at 16.1%, and high at 13.7%.

For Pinto, the nose-to-nose performance of the high end in a raging market marks a tectonic shift that's likely to persist for at least two years. To foresee where the different price tiers are heading, it's important to examine the confluence of highly favorable forces propelling all housing, and how the pandemic-driven, work-at-home economy is supercharging the high end. Let's start with the powerhouse demand picture.

To forecast prices in the months ahead, Pinto collects a large, representative sample of the data on loan applications submitted to FHA, Fannie, and Freddie and other government agencies, as well as private banks. Those are called "rate lock" numbers, since the contracts are signed when the lenders set the mortgage rate. That data allows him to project prices into the future, well before the sales are a matter of public record. Based on that information, he's projecting that prices will accelerate in future months even exceeding the rate reported for January, probably in all price tiers.

That methodology led Pinto to accurately predict that what he calls “HPA,” for home price appreciation, was heading for double digits earlier this year, when the rate of increase was much lower. Housing started 2020 on a tear. By early March, purchase contracts were exceeding same-week 2019 levels 51,000 to 33,000. Surprisingly, the COVID outbreak sidelined buyers for only about seven weeks.

From mid-June to the end of November, newly signed contracts were running at about 50,000 a month on average, far above the 35,000 registered in 2019. After taking a seasonal, year-end dip, rate locks spiked again, running around 60% over 2019 levels for the rest of the year. Those big contract numbers foretold a giant jump in sales in the months ahead, and showed momentum so strong that it was almost certain to keep building.

As America's hunger for houses intensified, the stock of homes for sale kept shrinking. Pinto offers four reasons for the inventory crunch. First, older baby boomers in their sixties and seventies are staying longer in their homes instead of downsizing to apartments, in part because the pandemic makes having space for hosting the family so attractive. Second, in places like the Carolinas and Texas, where building has been relatively plentiful, it's been taking longer and longer to get land zoned and approved for new construction. Third, severe land use restrictions in the Northeast and much of the West continue to keep a tight lid on fresh supply. Fourth, COVID magnified the damage from those barriers by shutting down construction for a couple of months in the spring and summer.

The result was a perfect gale that drove inventories to historic lows. Since January 2020, the number of homes listed for sale has cratered from 1 million to 600,000. “Months of supply,” the time required to sell all listings at the current pace, has fallen in that period from 3.3 to 2.0 months. That's less than half the five-month stock that, Pinto reckons, marks a balanced market. Remarkably, the number for homes in the medium-high category is a paltry 2.2 months, and the high end stands at 4.7 months, about half the 8.9 reading last April.

Bigger, newer, more expensive

The combination of gigantic demand and ultra-tight inventories is sending prices skyward. And the biggest leaps are frequently coming in metros where newly mobile, high-income families are moving to buy a much bigger, newer house for a lot less money, while the exorbitantly priced locales they're leaving are posting the lowest gains.

The biggest winner is Phoenix. From January 2020 to January of this year, its annual appreciation rate, or HPA, expanded from 9% to a nation-leading 14.5%. Like Phoenix, Sacramento benefited from the outflow from L.A. and San Francisco, as high and medium-high HPAs touched 18.1% and 19.7% respectively. Other winners from the Great Arbitrage were Riverside, Calif. (medium-high 17.4%), Tampa (20.5%), Nashville (16.5%), and Atlanta (14.1%).

The housing bargains in Columbus, Ohio, are drawing affluent work-from-homers from Chicago, pushing medium-to-high prices up 16% from January 2020. A coastal surprise is Philadelphia, where the HPA for the high grouping zoomed from 1.5% in January 2020 to 18.2% in December. The giant price gap between Philly and Manhattan and its burbs created a vacuum pulling high-earners from cramped condos or small homes to land bigger, cheaper homes in the City of Brotherly Love. The trek on Amtrak to visit their Big Apple offices once or twice a week takes just 90 minutes or so. Providence, says Pinto, is superhot, thanks to the outflow from Boston. Newark and Asbury Park, N.J., are feasting from the stream of Manhattanites seeking great buys across the Hudson.

Where are mortgage rates heading?

The big question is whether increasing mortgage rates will flatten the HPA curve or send it downward. The 30-year benchmark has already vaulted from 2.65% in early January to 3.25%. Pinto believes that if rates reach 4%, national prices will keep rising in the high single digits. "It would take over 5% to end the party," he says. "We're nowhere near that now."

The spike in the 30-year, he says, will show no effect in April and May because those deals are already done. So for those months, prices should keep rising in the 13% to 14% range. But the higher rates will start to bite in late May and June. By then, appreciation should slow to 9% to 10%, says Pinto. "That's still a very fast pace, much faster than at any time in the last 10 years, except for the recent increase in rates," he adds.

But somewhat higher monthly payments, he says, won't undermine the fundamental shift that's lifting prices of the more expensive homes in highly affordable metros. "A 3.5% rate won't stop families from moving from San Jose to Phoenix, where they can get a lot more house for 30% less," he says. He compares a 1,400-square-foot home in San Jose that sold for $602,000 to a 2,200-square-foot abode in Sacramento at $430,000, and a bigger stucco model in Phoenix at $384,000. "Families that make that move get much more space, pay a lot less per month, and pocket the cash from selling their home in Northern California," he says.

For Pinto, it was the COVID lifestyle that turned a tremor, already building, into an earthquake. "In the past, it was as if California and New York were captive markets," he says. "If you worked there, you had to pay big to live there. Prices kept getting more unaffordable for 45 years in those expensive markets. The perception until recently was you had no choice but to live in San Jose, or San Francisco, or Seattle. But the pandemic broke the shackles. An exodus on this scale has never happened before. At the end of the day, the free market will prevail." It took decades to happen, but the pandemic unlocked the gates. The best bet is that the new incarnation of the Great Land Rush will keep running on strong legs.