BOSTON (TheStreet) -- Enough companies have reported third-quarter earnings to reveal the state of U.S. business. Of the S&P 500's constituents, 284 have released financial results, with 77% of those beating Wall Street's estimates.

Still, analysts have been cutting earnings-per-share estimates. The bottom-up EPS estimate for S&P 500 companies for the fourth quarter now stands at $25.03, down 3% from Sept. 30.

The decline "reflects the sharpest drop in earnings expectations for the first month of a quarter since the second quarter 2009, when earnings estimates fell 7% during the month of April 2009," says John Butters, a senior earnings analyst at FactSet Research.

Investors have turned their attention to the economy and the European debt crisis. The

S&P 500

is on track for its best monthly performance in 37 years after European leaders reached approval for a writedown of Greek debt and an increase to the European rescue fund. In addition, a strong reading on U.S. gross domestic product last week assuaged fears that a recession was looming.

Nevertheless, the earnings docket is packed for this third peak week of reports -- 103

S&P 500

companies and two on the

Dow Jones Industrial Average

. Consumer trends will come into the spotlight with reports from

MasterCard

(MA) - Get Report

and

OpenTable

(OPEN)

.

Kraft Foods

(KFT)

and

Pfizer

(PFE) - Get Report

are the two Dow components with results due this week, but what they have to say can't be extrapolated across other industries, nor will they likely show different trends than counterparts that have already reported.

Similarly,

Clorox

(CLX) - Get Report

probably won't give a better indication of global demand for consumer goods than what

Procter & Gamble

(PG) - Get Report

has said. And

AIG

(AIG) - Get Report

, once the biggest U.S. insurer, "is more of a curiosity than it is a leading indicator," says Paul Nolte, director of investments at Dearborn Partners.

One industry that will be in focus is media, with

News Corp.

(NWS) - Get Report

,

CBS

(CBS) - Get Report

,

Comcast

(CMCSA) - Get Report

,

Time Warner

(TWX)

and

Sirius XM

(SIRI) - Get Report

on tap. But what each says about advertising revenue, subscriber trends and the shift to digital content may not alter views of the broader economy.

Several companies that recently held initial public offerings will open their books on the previous quarter, including

ZipCar

(ZIP)

,

Dunkin' Brands

(DNKN) - Get Report

and

LinkedIn

(LNKD)

.

That leaves credit- and debit-card processor MasterCard as one of the key reports for investors this week, even though rival

Visa

(V) - Get Report

already posted quarterly results.

"This is everywhere. It's not just about U.S. consumers, it's worldwide," says Joseph Doyle, co-portfolio manager of the

Manor Growth Fund

, of MasterCard. "They're such an important part of the network you take for granted for how you buy and sell stuff. And they make a percentage of everything that's done."

MasterCard, which went public only five years ago, has seen its share price surge almost 60% this year despite concerns that the credit crunch and high unemployment would crimp consumer spending. Additionally, the Durbin amendment of the Dodd-Frank act, which targeted interchange fees that processors like MasterCard take for themselves, hasn't slowed the company's growth.

Doyle says the investment story with MasterCard isn't only the dependence on consumer transactions. "It's about the opportunity in the increasing prominence of electronic processing and Internet-based processing of transactions, replacing cash and checking," he says.

The Durbin amendment, part of the financial-reform bill passed over a year ago, changes the rules to favor market-share aggressors like MasterCard and makes it more difficult for market share defenders such as Visa, Doyle says.

"It's dawning on analysts that MasterCard might end up in the driver's seat in the U.S. debit card business," he says.

Meanwhile, OpenTable may slip through the week of earnings without much fanfare, but the company is in the middle of a secular trend. OpenTable, which facilitates restaurant reservations on the Internet, has a network of over 20,000 restaurants across the country, seating almost 24 million diners in the second quarter alone.

The opportunity in the restaurant-reservation sector is so big, however, that even

Google

(GOOG) - Get Report

is muscling in. The company paid $150 million to buy restaurant-ratings guide

Zagat

nearly two months ago.

"With OpenTable, it's a good one to follow going down the road," says James Paulsen, chief investment strategist at Wells Capital Management, a firm with $333 billion in assets under management. "Eventually, OpenTable could end up being a good leading indicator of consumer activity."

The shift to a new technology is enough to drive revenue, so investors will want to see what OpenTable can say about restaurant bookings, which could give an inside look at consumer demand. Others, including Dearborn's Nolte, question how much can be learned about the U.S. economy from restaurant-reservation data from OpenTable, even if it does offer a peek at consumer trends.

"

McDonald's

hits a broad base," Nolte says. "How much of the market are we talking about with OpenTable, in terms of overall revenue?"

That skepticism has played a large part in the stock's decline this year. OpenTable shares are down more than 30%, with the drop sparked by the resignation of CEO Jeffrey Jordan in April.

MasterCard is set to report quarterly results Thursday before the opening bell, with analysts expecting revenue of $1.7 billion and earnings of $4.82 per share, according to a poll by Thomson Reuters. OpenTable, which will post quarterly numbers on Tuesday after the close of trading, should report revenue of $35.9 million and a profit of 30 cents a share.

-- Written by Robert Holmes in Boston

.

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