Will consumers come to economy's rescue?

Shoppers looking at Michael Kors bags at Macy's in New York.
Scott Mlyn | CNBC
Shoppers looking at Michael Kors bags at Macy's in New York.

The fate of the global economy is increasingly in the hands of American consumers.

And—judging from the latest data—it's not clear that they're coming to the rescue.

With growth slowing from Beijing to Berlin, the U.S. economy this year has bucked the trend, thanks, in large part, to a strengthening job market that helped households boost spending.

But with the stock market stumbling and Ebola headlines spreading, American consumers took a break in September, sending retail sales 3 percent lower than the month before.

Read MoreRetail sales give cautionary sign on demand

Part of the pullback represented an expected slowdown in car sales last month after red-hot sales in August.

What's more, falling gasoline prices pulled down the retail sales number when measured in dollar terms.

"Even adjusting for those two (car and gas sales), sales were still off," said Joel Naroff at Naroff Economic Advisors. "We didn't even shop online, which is a real surprise."

Food prices have also been trending lower, and forecasters expect that to continue—thanks to a worldwide, bumper crop in grains that have pulled the price of those commodities sharply lower.

The worry is that a slump in spending could feed on itself, as sluggish sales force manufacturers to reduce productionalong with workers' hourscutting into households spending power. U.S. exports are already under pressure as a rising dollar has made U.S. products more expensive for overseas customers.

So far this year, the dollar is up 5 percent against other major currencies; if the economies of the rest of the world continue slowing, that rise will likely continue. That could throw more cold water on U.S. exports, one of the key drivers of the ongoing recovery.

But lower food and gasoline prices also should give U.S consumers a spending boost as their shopping dollars go farther at the gas pump and grocery store. A rising dollar increases their buying power when shopping for imported goods.

Read MoreBumper crop brings food price relief for consumers

"(For) the American consumer, this is an early Christmas present," said Laurence Fink, CEO of BlacRrock. "So it should be good for U.S. retailers."

That means the next 10 weeks could be critical for the U.S. economic recovery. So far, most forecasters expect U.S. consumers to step up to the task of keeping the recovery alive. The National Retail Federation is predicting a respectable 4.1 percent bump in holiday sales compared with last year

That would be a welcome gain from last year's 3.1 percent growth, a season marked by lousy winter weather and widespread angst over the government's self-inflicted shutdown.

In the meantime, last month's shopping pause will likely also give pause to Federal Reserve policymakers considering a possible increase in interest rates. That move is likely on hold until the American consumer makes their intentions better known.

"(The latest data) is hardly indicative of a strong economy with a Fed poised to raise rates," said Lindsey Piegza, chief economist at Sterne Agee.