Another critical variable in every stock market relates to which sectors dominate the capitalization of the index.

FORBES: Deathtraps In The World's Bourses

Avoiding Google and Microsoft or at least underweighting them was the critical variable in gaming the tech index this year.

FORBES: Where To Load Up, Where To Go Lightly In Russell Growth, S&P 500

Siting decisions for major facilities are among the most important a company makes and reliable, low-cost energy is a critical variable.

FORBES: EBay And Republican Lawmaker Score Clean Energy Win In Utah

The price of corn is a critical variable in the world food equation, and food markets are on edge because U.S. corn stocks are plummeting due to the ethanol mandate.

FORBES: Feds Could Lessen Drought Impacts But Don't Bet The Farm On It

It is critical to bundle all future variable costs of supporting the customer in order to fairly estimate the future contribution.

FORBES: The Dangerous Seduction of the Lifetime Value (LTV) Formula

But when taking the entire 500 stocks that make up the index as a whole, the multiple that is being applied as an average to all becomes less variable, although critical to assessing prices.

FORBES: The Case for Bulls in 2012

The NGIPS platform is critical for clean energy, especially variable resources like wind power and solar photovoltaics.

FORBES: Microgrids: Ten Clean Technologies Needed to Win the Next Naval War

After the canvas was cleaned, it became clear that Ensor's nightmarish vision of a boisterous city boulevard teeming with banners, placards and a massed, modern rabble was shaped not only by the artist's deep-seated pessimism but by his critical view of contemporary art, captured here in dazzling displays of virtuoso painting that are as variable, original and richly parodic as the painter's darkly comic brigade.

WSJ: A Macabre Kingdom of Masks | James Ensor | Christ's Entry Into Brussels in 1889 | By Mary Tompkins Lewis