In August, the Commerce Department said U.S. retail spending was flat in July. Shown, a newly opened J.C. Penney store at the Gateway Center Mall in Brooklyn, N.Y. Getty Images
Summer brought companies some hopeful signs of economic recovery. This fall, the optimism will be put to the test.
That's because it is unclear whether consumers—the engine behind more than two-thirds of the American economy—are ready to resume spending at significant levels.
Signals are mixed. After years of lackluster growth, corporate revenues for large companies grew more rapidly in the second quarter, and company guidance suggests that trend will continue in the second half of the year. The Conference Board said consumer confidence picked up in August.
Employment continued to tick upward. Gross domestic product jumped in the second quarter as businesses and consumers made up for the first quarter's lousy weather. Economists are predicting growth at a 3% rate for the second half, and 2% growth for the full year.

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Still, the retail industry, tied more closely to consumer spending than any other, is struggling. In August, the Commerce Department said U.S. retail spending was flat in July. And household spending declined by 0.1% in July, the first drop in personal spending since January.
Investors are clearly nervous as well. For much of August, retailers and a grocer made up most of the 10 worst-performing stocks in the S&P 500 index: Coach Inc., down 34% for the year;Whole Foods Market Inc.,down 32%; Mattel Inc.,down 28%; Staples Inc., down 26%; and Bed Bath & Beyond Inc. and Best Buy Co , both down about 20%.Avon Products Inc. andFossil Group Inc.  also lagged behind, down about 18% and 16%, respectively. The Dow Jones U.S. Retail Index has struggled to mark gains so far this year.
One indication that investor anxiety may be justified: When retailers talk about sales growth, many are reserved in their projections. On Aug. 26, Best Buy predicted a tough holiday season marked by steep discounts and weak demand after recording a 2% drop in sales at U.S. stores open at least 14 months. And in some sectors, including low-end dollar stores, companies may be benefiting more from market share than broader growth.
"Revenues are doing better than they were," says Howard Silverblatt, senior index analyst at S&P Dow Jones Indices. But companies "don't think consumers are going to be spending that much more."
At Home, a closely held Texas home-furnishings chain with 75 locations in 21 states that advertises low prices, says sales are up 20% year over year. The company is seeing new customers, more-frequent visits and higher ticket prices amid mediocre increases in overall consumer spending, which means much of the growth is coming at the expense of competitors, Chief Executive Lee Bird says.
"There's growth here, but we're getting a disproportionate share of that," Mr. Bird says. "We're definitely taking share while growing with a sluggish economy."
And then there is the question of how much capacity consumers have to spend. What isn't spent is generally saved. But the savings rate in the U.S. is about 5.3%, at or below recent trends.
In other words, there may not be enough untapped spending power sitting on the sidelines, waiting for confidence to improve, to fuel a strong consumer recovery, says Dean Baker, an economist and co-director of the Center for Economic and Policy Research in Washington.
So far, that has been true for customers of Hibbett Sports Inc., a sporting-goods retailer with primarily lower-income customers in the South, Southwest, Midwest and mid-Atlantic, says Scott Bowman, the company's chief financial officer. The company saw sales inch up just 0.1% in the quarter ended Aug. 2, excluding new and closed stores.
"That lower-than-average-income consumer has a few more headwinds than the upper-tier consumer, with static wage growth, underemployment," Mr. Bowman says. "I think it will get better, but it will be gradual."
Still, consumers have managed to rally before. And some economists are more upbeat. While summer monthly sales figures looked grim, the year so far hasn't been terrible. At about 4%, year-over-year retail sales growth is reasonable, says Mark Zandi, chief economist for Moody's Analytics.
Consumer spending overall also is roughly matching income growth, with consumer confidence at prerecession levels and debt payments at record lows, he added.
"As long as the job market continues to improve, and it is, then I think consumers will continue to ramp up their spending consistent with that," or possibly higher if they decide it is safe to borrow more, Mr. Zandi says. "I think it is fair to say that consumers are doing their part for the recovery."