More generally, the pandemic turned the kaleidoscope of U.S. migration, and many families—especially many high-income families with work-from-wherever jobs—are shopping around for sunny, spacious real estate and bidding up prices wherever they land. “We’ve never seen migration like this,” executives at Toll Brothers, the real-estate company, recently said on an earnings call. “Just shy of half the buyers are coming from out of state” in the hottest markets of Idaho, Texas, and Florida. When people leave multimillion-dollar houses in, say, Los Angeles to plunk down $1 million on a house that was worth $500,000 a year ago, they turn a merely frenzied housing market into a once-in-history, hair-on-fire, what-the-hell-is-happening bonanza. Supply issues are just as important. Years of insufficient building and a construction pause during the pandemic have led to low inventory. Seniors, who in previous decades sold their homes to downsize, are now more likely to “age in place,” which is keeping millions of homes off the market. Plus, some builders are putting their projects on hold because of the sudden tripling of lumber prices, which could delay the construction boom this country so badly needs.