That the stock market and the economy should confirm each another, with stocks perhaps leading, is one of those truths we hold to be self-evident. But all markets are not created equal.

I devote a lot of attention to linkages and causal relationships between markets, as well I should; the information content in a market that behaves as expected is quite low. We learn of impending changes only by studying why the truths we held to be self-evident were in fact not, and by incorporating into our models and thought processes the information gleaned from previously unnoticed relationships.

It's a humbling task and quite possibly condemned to permanent frustration. George Bernard Shaw stated, "The reasonable man adapts himself to the world; the unreasonable one persists in trying to adapt the world to himself. Therefore all progress depends on the unreasonable man." We can update this to trading and market analysis:

Winners have no incentive to refine their analysis; losers study their past mistakes. All financial theory, therefore, is derived from the backward-looking attempts of unsuccessful traders to avoid the recurrence of an event within a situation that will never again exist.

All of this windup is to address three related developments at the end of the past week. The first was the declaration by the National Bureau of Economic Research that the recession ended in November 2001 -- a bit of an eyebrow-raiser, to be sure, but one that I will accept out of lack of a convincing argument otherwise. To return to Ronald Reagan's query, are you better off now than you were in November 2001? Many cannot answer in the affirmative.

The second was that the smoothed growth rate of the Economic Cycle Research Institute's weekly leading index rose to its highest level since May 1987. ECRI's Anirvan Banerji, a contributor, noted that it has been driven higher by "soaring growth in money supply plus mutual funds and near-record highs in mortgage applications for purchases."

With all respect to ECRI, please consider that both money supply and the mortgage industry have been distorted by the Fed's rate-cutting actions, and as a result, their roles within the economy of 2003 are likely to be quite different from the past. I'd feel differently if the money supply were rising from a surge in commercial and industrial loans or if the rise in mortgage applications was driven by a surge in personal income.

The third was an email from a RealMoney reader who asked, "How much can stocks go down while the economy is going up? Do present-day investors have a lack of experience with a market-down, economy-up disconnect?"

Stocks and the Economy Are Co-Dependent

Equities represent the discounted stream of future dividends. As dividends are generally but not necessarily paid out of earnings -- there are many examples of firms borrowing to pay their dividends -- we should expect stocks to rise if dividends are expected to grow by an amount greater than interest rates will rise. But it doesn't always follow that earnings will rise as the economy strengthens: A strong economy attracts new investment into an industry, which often places downward pressure on operating margins. Nor does it follow that a weak economy is necessarily bad for any and all stocks: Just think back to the 1970s boom in oil stocks or even the recent strength in homebuilders.

In addition, strong economies often are accompanied by rising interest rates. The short and violent bear markets of 1962 and 1987 both were precipitated by rapid increases in short-term interest rates. And to complete the matrix, a weak economy can launch a strong stock market if investors convince themselves that things will soon be much better. This last situation appears to describe the stock market since March reasonably well.

The chart below is striking in how few times the total return on the S&P 500 and the GDP parallel one another. During the two great bull phases of the postwar era, 1949-66 and 1982-2000, the growth rate of total return far exceeded the growth rate of real GDP, and the opposite was true for the 1966-82 trading range and for the post-2000 market.

S&P 500 and GDP Are Different
Source: Bloomberg

In direct answer to the reader's question, we've seen several episodes of falling stocks in a growing economy: 1957, 1962, 1966, early 1984, 1987 and today. All previous episodes were characterized by rising short-term interest rates. Given today's weakly growing economy and the strong but qualified ECRI leading indicator, we might be forgiven for concluding that we won't see a rising economy/falling stocks scenario.

It Is Never That Simple or Linear

Econometric analysis, the art and science of modeling data, is really the art of analyzing residuals, the error term left over after we explain variable Y with some set of variable X. These residuals should be a white noise, or completely random, process. If there's a visible pattern or if they're correlated, that's a sign something is missing in the analysis. That appears to be the case trying to explain the growth rate of deflated S&P 500 total return with the growth rate of deflated GDP.

Something Is Missing
Source: Howard Simons

These residuals are anything but a white noise process. They contain a huge and consistent turn downward during the 1966-82 range and an equally huge and consistent turn higher from 1982-2000. We're in the midst of another too-consistent move right now. If the relationship between stocks and GDP was strong and predictive, none of these features should be visible.

The question then becomes what macroeconomic variables can account for the long periods when stocks either outperform or underperform the economy. I'll try to answer this next week. A few thoughts are in order, though. Several important variables, namely energy prices and currency exchange rates, didn't trade in a free market until the early 1970s, and therefore aren't useful for longer-term analysis. The interest rate ceilings of Federal Reserve Regulation Q didn't disappear until the early 1980s, and financial derivatives didn't reach their current level of acceptance until then, either.

The answer to this question, if it can be found, will help us interpret the financial news a little better. Until then, remember that you're trading stocks and bonds, not GDP futures.
Howard L. Simons is a special academic adviser at Nasdaq Liffe Markets, a trading consultant and the author of The Dynamic Option Selection System. Under no circumstances does the information in this column represent a recommendation to buy or sell securities. The views expressed in this article are those of Howard Simons and not necessarily those of NQLX. As a matter of policy, NQLX disclaims the private publication of materials by its employees. While Simons cannot provide investment advice or recommendations, he invites you to send your feedback to Howard Simons. has a revenue-sharing relationship with under which it receives a portion of the revenue from Amazon purchases by customers directed there from