Fed rate hike falls harder on housing than AI investment

10-year Treasury yield crossed 5% on Sept. 14 for first time since 2023

The Federal Reserve raised its benchmark interest rate by a quarter percentage point on Sept. 16, 2026, lifting its target range to 3.75% to 4% in a unanimous vote. In commentary republished by UPI on Sept. 17 from The Conversation, John W. Diamond, director of the Center for Public Finance at Rice University’s Baker Institute, argued the Fed probably had little choice but to act. Diamond wrote that “markets had already expected the hike, and if the Fed had failed to deliver, it might have pushed longer-term interest rates even higher amid concerns it was becoming less wedded to that target.” His central observation is that the rate hike will fall disproportionately on sectors already struggling and highly sensitive to interest rates while having less effect on the AI investment cycle, making the U.S. economy, in his words, look like one “moving at two very different speeds.”

The Fed’s policymaking committee described inflation as “elevated” and noted that other economic indicators remain strong, from productivity to investment to domestic spending. The committee described economic activity as “expanding at a solid pace” and said it “will support a timelier return” to its 2% annual inflation target. The decision tracks recent comments by Fed Chairman Kevin Warsh that restoring price stability is central to the Fed’s credibility. In a key August speech, Warsh called the 2% goal a “firm, fixed target” — a turnaround from his more ambiguous July comments.

The data behind the decision shows inflation running above target. Consumer prices rose 0.4% in August and 3.4% over the prior 12 months, Diamond noted. The war with Iran has pushed oil prices back above $100 a barrel, raising costs for gasoline, diesel, transportation and production. The labor market, meanwhile, has not cracked: the economy added 162,000 jobs in August and the unemployment rate held at 4.1%. More than one-quarter of unemployed Americans have been out of work for at least six months.

Taken together, those numbers suggested there was room for the Fed to hike rates, given that the economy isn’t sliding into recession, Diamond wrote. Investors overwhelmingly expected the rate increase.

When the Fed hikes short-term interest rates, it slows economic activity by making borrowing more expensive and saving more attractive. That mechanism works particularly well when consumers decide whether to finance a house, purchase a car or take on additional debt, and it discourages businesses from making investments when the expected return is only modestly above their financing costs. As demand slows, businesses have less room to raise prices, easing inflationary pressures.

The housing market provides the clearest example of the uneven hit, Diamond wrote. Persistently high mortgage rates and diminishing affordability are weighing on the housing market, while consumers are carrying ever more expensive credit card and auto debt. Many small and traditional businesses are also in a bind, facing substantially higher financing costs than they did several years ago. Mortgage rates are shaped mainly by long-term Treasury yields, inflation expectations and the market’s view of the Fed’s path, but a Fed hike still signals that policymakers see inflation as more persistent, putting upward pressure on longer-term rates as markets price in further increases.

The lock-in effect reinforces reduced mobility. Millions of homeowners financed their houses when mortgage rates were 3% or 4% and have little reason to sell and take on a new mortgage at much higher rates. With mortgage rates recently near 7%, Diamond expects fewer home sales, reduced mobility and continued pressure on prospective buyers, with renting becoming relatively more attractive for those priced out of buying.

Higher-for-longer rates also change how consumers save. When interest rates were near zero, savers earned almost nothing on safe assets. Today, Treasury securities, money market funds and other relatively safe assets offer meaningful returns, and higher rates tend to shift incentives away from borrowing and spending and toward saving. With consumers stretched by inflation and increasingly dipping into their savings, however, that saving shift may be less pronounced.

The costs facing small businesses and households reflect rising yields on longer-term U.S. government debt, which have been climbing for months on a mix of factors: long-term inflation concerns tied to soaring U.S. government debt, geopolitical risks driving up energy costs, and ongoing financing demand for AI. On Sept. 14, the yield on the 10-year Treasury crossed 5% for the first time since 2023.

AI investment, by contrast, is unlikely to be much deterred. Warsh noted in August that more than half of recent capital-spending growth could be attributed to the AI buildout, and Diamond wrote that investment in AI — through data centers, computing capacity or related infrastructure — has been booming while crowding out other kinds of investment. The companies spending billions on computing infrastructure are doing so because they expect potentially enormous returns; if those expected returns are exceptionally high, Diamond wrote, a modest increase in borrowing costs may do little to alter their investment decisions. “That stands in sharp contrast to a prospective homebuyer getting sticker shock from mortgage rates nearing 7%,” Diamond wrote.

The federal government’s interest expense adjusts more slowly. A Fed rate hike doesn’t immediately increase the interest rate on all outstanding federal debt, since most Treasury notes and bonds carry fixed rates until they mature. But as the Treasury issues new debt and refinances maturing securities, today’s higher rates gradually become tomorrow’s higher federal interest expense. The national debt recently topped $40 trillion, and that rise in interest costs is a main reason some economists are sounding alarms about the long-term fiscal trajectory.

Diamond described a U.S. economy facing a reality in which both short- and long-term rates stay higher for longer. The federal government, households and businesses are all adjusting to a borrowing environment that looks substantially different from the one that prevailed for much of the previous decade.