New Delhi, Aug. 19 -- STOCK MARKETS, Wall Street-wary politicians and like-minded commentators repeat ad nauseam, are not the real economy. The S&P 500 index of America's biggest firms is up by 12% this year, setting one all-time high after another. Meanwhile, they point out, American GDP growth has slowed, employment has stalled and consumers feel more downbeat than at just about any point since the University of Michigan started keeping track in 1952.

All true-and nauseatingly familiar. Less remarked is the fact that the S&P 500 and the world's other benchmark indices are no longer the real stock market, either. Rather than mirroring the universe of domestic equities, they increasingly reflect the fortunes of a few corporate giants, wh...