Investors -- certainly U.S. stock investors -- would be wise to keep one eye on the price of oil, currently pushing $90 per barrel. Oil traded up 10 cents to $89.29 on Monday at mid-day.

And the reason is obvious enough: once again, oil is approaching the danger zone, from a U.S. GDP growth standpoint.

No one knows precisely at what point oil begins to substantially hinder consumer spending and slow commercial activity -- but this much is known: every $1 per barrel rise in oil decreases U.S. GDP by $100 billion per year and every 1 cent increase in gasoline decreases U.S. consumer disposable income by about $600 million per year.

The U.S. economic recovery will slow more than previously estimated, to 2.5% GDP growth in 2011, down from the previously-estimated 2.8% growth seen last month, according to a new survey of economists by Bloomberg News.

Bloomberg News polled 59 economists September 1 through 9, and the group sees elevated unemployed weighing on consumer spending, moving forward, with companies also scaling-back investment plans.

Those surveyed also expect the U.S. unemployment rate to remain above 9% in 2011. Despite a 67,000 rise in private sector payrolls in August, the U.S. unemployment rate rose to 9.6% from 9.5% in August, as more unemployed Americans who had stopped looking for work, resumed their job search, and hence were counted as unemployed.

This morning, the Commerce Department announced that the economy grew at a slower pace than previously thought in the April-to-June period. The gross domestic product grew at a 1.6% rate during the period, revised down from an initial estimate of 2.4%, and far slower than the 3.7% pace in the first quarter. Yet Wall Street actually sighed in relief because investors and economists had expected an even worse number.

Despite the euphoria on the Street over the not-as-bad-as-expected numbers, we are still faced with a stark reality as the economy has lost "significant momentum" lately. In fact, most believe that the third quarter will hold similarly weak growth.

For the first time in history, U.S. government debt -- now $13 trillion -- will surpass GDP in 2012, based on forecasts by the International Monetary Fund. Bill Gross of PIMCO calls this a "debt super cycle."

The key problem with such a huge debt is that investors will demand a higher return, which translates into higher interest rates. The interest cost alone on $13 trillion will put an added burden on the government and the people.

Bill Gross further commented that "If real interest rates were ever to go up instead of down," our economic growth will not be enough to support borrowings.

The Commerce Department announced Friday morning that the economy grew at a 3.2% rate during the first quarter of 2010, below expectations that called for the GDP to increase 3.4%. Consumer spending increased at the fastest pace in the past three years, serving as the impetus for the GDP growth.

Consumer spending increased at a 3.6% annual rate, with business investments in equipment and software increasing at a pace of 13.4%. In the past year, the GDP has increased 2.5% driven by a 5.6% increase in the fourth quarter.

The final number is in for the U.S. gross domestic product (GDP): the economy grew at a brisk 5.6% rate in the fourth quarter (according to the Commerce Department). This is the best performance in six years.

As should be no surprise, consumer spending was still light. But there was a nice spark from exports as well as corporate profits. Hey, is it any wonder the stock market has been bullish?

The Commerce Department gave us a nice little surprise this morning, revising up its fourth-quarter estimate of the Gross Domestic Product. Economic activity grew by 5.9% during the fourth quarter, which was the fastest rate since the third quarter of 2003. Last month, the Commerce Department estimated that the GDP rose by an annual 5.7% during the fourth quarter.

Here is the thing, this figure was in line with expectations of economists, so all of the glad handing may be a bit premature. Inventory liquidation slowed more than experts expected, which contributed the most percentage points to the GDP since the fourth quarter of 1987. Business spending increased 6.9%, which was far better than the earlier estimate of 2.9%. It added 0.62 percentage point to the GDP.

Consumer spending had its largest fall this year, thanks to the end of the "Cash for Clunkers" program. And, incomes were flat. No change to the money coming in and a drop in the cash going out translates to an impediment to economic recovery.

In September, consumer spending fell 0.5%, the first decline in five months and the worst in nine. Wages and salaries dropped 0.2%, effectively offsetting the 0.2% up-tick in August. The economy did grow in the third quarter of 2009, hinting that the worst recession in 70 years may be coming to a close, but the tough September suggests we still have some work in front of us.

This morning, the White House reported that President Obama's stimulus package has created or saved 650,000 jobs -- of course, this time the Obama Administration promises that the new figures will be "more accurate" than in the past. As for the jobs saved or created, the administration based its finds on roughly $150 billion in spending from the $787 billion stimulus package. These "more accurate" numbers are taken from state reports and private companies. The White House did note that the actual number of jobs created thus far is "likely closer to 1 million" because this report looked at only $150 billion of the $339 billion invested in the American Recovery and Reinvestment Act funds spent.

It appears that the U.S. economy may finally be dragging itself out of the economic doldrums. At least, that is what the third-quarter Gross Domestic Product indicates. The GDP showed that the U.S. economy grew at a 3.5% annual pace in the third quarter, snapping a four-quarter contraction streak.

The growth is attributed to the massive government stimulus, which led to higher consumer spending. In addition, a reduction in inventories and robust government spending helped spur growth in the third quarter. But even excluding the influence of auto sales, production and inventories, the economy grew 1.9 percent last quarter.

Early estimates of a contraction in the U.K. economy were not enough. First quarter 2009 estimates were revisited, showing a 2.4% fall in gross domestic product from the last quarter of 2008 to 2009. This downward revision made the first three months of the year the worst since people wore skinny ties, hated communism, and bore nicknames like "Buzz."

In the second quarter of 1958, U.K. GDP plummeted 2.6%, though the 2.4% threshold matches the depths hit in 1979. The original 2009 Q1 estimate was -1.9%, according to the Office for National Statistics in London.

While most headlines in the financial media recently reported economists and institutions projecting the end of the recession in the second half of the year, the IMF said Monday the worst of crisis may be yet to come.

While those who think we are out of the woods believe this recession will have just one dip, the IMF seems to advocate what is known as a "double dip" recession. They believe that the expected upward swing in Gross Domestic Product for developed nations will just precede yet another economic collapse in the first half of next year.

The newspapers are looking ahead to this Tuesday's G-20 summit in London. Since the leaders who show up there represent countries that control 80% of the world's economy, it could be an important meeting. If you live in the U.K. or U.S., your leaders will be attacked by those in other countries who believe that they should not be asked to bail out the errors of Anglo-American capitalism. Beyond that, little of substance is likely to be accomplished.

However, in an alternative universe, the G-20 meeting might actually accomplish something. Specifically, it could get agreement on six principles on which to rebuild American capitalism. Here's what I think those would be:

• Grow through technology-based innovation. The United States used to be admired around the world for its ability to create new industries. In the 1990s, an Asian government wanted to emulate our success and asked me to discuss how the United States turns innovation into economic growth. Unfortunately, since 2000 our ability to take brilliant ideas from our top universities and turn them into venture-backed companies that sell their shares to the public to fuel the creation of new industries has largely been broken. If there is to be growth, it should come from reviving this process.

A digital clock in New York City counts up the U.S. National Debt. But the current administration broke the clock which only had enough digits to count up to $9,999,999,999,999. As Dick Cheney said, Ronald Reagan proved that deficits don't matter. I wonder whether this broken clock is proving Cheney wrong?

The clock has an interesting history. The now-deceased Manhattan real estate developer, Seymour Durst, built this sign in 1989 because he thought that the then $2.7 trillion debt was too high. The debt kept growing after he put up the sign but by the end of Bill Clinton's second term, it was down to around $5 trillion. Since January 2001, the national debt has grown to $11.3 trillion thanks to the $850 billion bailout bill.

The good news is that the clock, which currently counts the deficit by substituting a 1 for the $ sign that was there before, will be fixed next year -- adding two digits. Too bad fixing the clock won't make the U.S. economy any less perilous. At 81% of Gross Domestic Product (GDP), our national debt is way above the 60% that the IMF considers to be a risky borrower.

Peter Cohan is President of Peter S. Cohan & Associates. He also teaches management at Babson College and edits The Cohan Letter.

Today's worse-than-expected U.S. Gross Domestic Product report for the first quarter brings economics back to the fore as far as share prices are concerned.

With various other measures, including the Index of Leading Economic Indicators, signaling that a recession is imminent -- if it hasn't begun already -- history suggests the stock market could be in for a rough ride in the period ahead.

Based on an analysis of data going back 50 years, the median return of the S&P 500 Index three months after a recession has started (as determined by the National Bureau of Economic Research) has been -4.77%. After six months, the return has been -8.54%.

Given that the current bull market has not experienced a 10% correction for nearly half a decade and is already long in the tooth by historic standards, the prospect that the economy is now heading off the rails can only add to a negative outlook for the U.S. equity market.

Michael Panzner is a 25-year veteran of the global stock, bond, and currency markets and the author of Financial Armageddon: Protecting Your Future from Four Impending Catastrophes and The New Laws of the Stock Market Jungle: An Insider's Guide to Successful Investing in a Changing World.