Economic theory says that in a competitive market, the cost of a pizza, like the cost of a copyrighted work, will fall to its marginal cost.

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In theory, he says, location should no longer be a source of competitive advantage in an era of global competition, rapid transport and high-speed telecommunications.

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In theory, when interest rates are dropping, PE ratios should be expanding because fixed income becomes less competitive with equities when interest rates are low.

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