If the retail sector is waiting on a dedicated corps of eager consumers, sales growth may be stalled for a while yet.

The Conference Board s consumer confidence index took another spill in July, after falling sharply in June. The index, which is based on a survey of 5,000 U.S. households, now rests at 50.4, down almost four points from a month earlier.

Two other Conference Board gauges of consumer attitude, the present situation index and the expectations index, declined in July by 0.7 points and 6.1 points, respectively.

Concerns about business conditions and the labor market are casting a dark cloud over consumers that is not likely to lift until the job market improves, says Lynn Franco, director of The Conference Board Consumer Research Center. Given consumers heightened level of anxiety, along with their pessimistic income outlook and lackluster job growth, retailers are very likely to face a challenging back-to-school season.

Retailers have already been affected by consumer unease. Retail sales slipped 0.5% in June and 1.1% May, according to the Commerce Department. Separately, personal spending edged up just 0.2% in May. (The June personal spending report is scheduled to be released Tuesday.)

The outlook for the consumer s attitude remains bleak. According to the latest Conference Board survey, fewer consumers expected an improvement in business conditions, more jobs or an increase in income in July than they did in the month prior.

Here s what two economists had to say about consumers lackluster mood and its impact on retailers.

Who s Talking : Peter Cardillo, chief market economist at Avalon Partners

The Gist: Consumers are suffering from large bouts of uncertainty, and they re likely to translate into more frugality this fall.

Consumers major concerns are the real estate market, taxes, the unemployment rate and the unknowns about health care, says Cardillo. They are driving more Americans to pay down debt or sock away savings.

Still, Cardillo says some of the angst may fade. I don t expect a double-dip recession, and with unemployment at high levels, that s the greatest concern, he says. Cardillo expects consumers mood will gradually improve, particularly if the stock market offers psychological encouragement. However, growth is likely to be slow.

Back-to-school sales are likely to attract consumers because they do have to spend on essentials, Cardillo says. But that s not necessarily good news for the retail industry. The consumer is quite frugal and continues to look for bargains.

Who s Talking: Brian Bethune, director of financial economics for Global Insight's United States Macroeconomics Group

The Gist: Consumer pessimism may be overdone, but it will still sting retailers.

It s hard to understand why there s been such a sharp downturn in consumer confidence, Bethune says. But I think it s the kind of situation that we ve seen where there are periods of improvement and then, all of the sudden, we hit the reset button and we get a pullback, he says. It s been a seesaw for some time now.

It seems like some of the pessimism that we saw more recently was overdone on the downside, and we re only starting to see some of the reality check that things aren t really that bad, Bethune says. But it s still troubling to see consumer confidence fall back after so many months of progress.

For retailers hoping for a strong back-to-school season, it s not good, he says, especially as they try to start the season earlier. However, the continued warm weather this summer may inspire buyers to continue purchasing summer gear for longer than expected, which should be a positive, he says. The weather is in their favor.