The Federal Reserve is in a tricky place as it tries to balance a weakening job market and strong consumer spending. The August retail sales report came out yesterday and showed a third month of increased spending.

Those retail numbers are growing more dependent on a smaller group of consumers. The top 10% of earners in the U.S. accounted for nearly 50% of spending in the second quarter, the highest level it’s been since this data first started being collected in 1989, according to Moody’s Analytics.

Soaring home values and financial markets have helped the rich transform into the wealthy. And the economy does benefit from this in some ways. In fact, it’s probably benefitting right now. 

“That has helped keep sales in the economy stronger than it would have been,” said Jim Wilcox, an economist at the University of California, Berkeley.

He said without the high earners, there’d be more people feeling inflation and less spending. And the unemployment rate would be higher. It’s currently 4.3%.

But the thing about wealth that’s based less on income and more on housing, stocks, and bonds is that those markets and the money tied up in them are more volatile. 

“And just as it has gone up by an enormous amount in recent years it can retrace some of that,” Wilcox said.

If that happens, high earners are going to feel less secure.

“It’s not like they’re gonna run for the bunker,” said Mark Zandi, the chief economist at Moody’s Analytics. “But they’d become more cautious.”

He said high earners would be more cautious about home renovations, new cars, expensive trips, and other spending.

“Even doing that, you know, becoming less aggressive in their spending would be enough to cause the economy some big problems,” Zandi said.

That’s because the spending happening by the majority of Americans is not enough to bankroll the economy. Zandi said spending has increased among the bottom 80% of earners, but not faster than the rate of inflation. Which means in some ways they’re actually pulling back. And of course, if top earners are feeling any pain, middle and lower-income people are hurting more. 

This imbalance of high earners propping up the economy is becoming more cemented.

“And it has created a self-reinforcing loop where more and more the economy is working for people at the top and not middle and bottom,” said Michael Linden, a senior policy fellow at the Washington Center for Equitable Growth.

That can show up in everything from the selection of stores that are at the mall to what kind of policy is prioritized in government.