‘Jenga Tower’ US Economy at Risk as Spending Slowdown Spreads

The surprising resilience of the US economy this year is masking underlying weakness among low- and middle-income households, as higher-income Americans continue to drive growth.

This dichotomy between the haves and have-nots isn’t new, but the economic strain is now bleeding from the lowest earners to the middle class, creating an even starker divide that some economists say makes the economy more susceptible to a downturn.

The richest 10% of households are fueling nearly half of total US spending, thanks to a stock market surge that has boosted wealth and in turn propelled economic output this year. Meanwhile, lower-income families ...