Older Americans like Harris are fueling a sustained boost to the U.S. economy. Benefiting from outsize gains in the stock and housing markets over the past several years, they are accounting for a larger share of consumer spending — the principal driver of economic growth — than ever before.

And much of their spending is going toward higher-priced services like travel, health care and entertainment, putting further upward pressure on those prices — and on inflation. Such spending is relatively immune to the Federal Reserve’s push to slow growth and tame inflation through higher borrowing rates, because it rarely requires borrowing.

Affluent older Americans, if they own government bonds, may even be benefiting from the Fed’s rate hikes. Those hikes have led to higher bond yields, generating more income for those who own such bonds.

The so-called “wealth effect,” whereby rising home and stock values give people confidence to increase their spending, is a big reason why the economy has defied expectations of a sharp slowdown. Its unexpected strength, which is contributing to stickier inflation, has forced a shift in the Fed’s plans.