An industrial cluster that can generate foreign earnings on such a scale is enviable.

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The relocation of manufacturing from upstate New York has weakened the industrial cluster, which in turn has greatly impacted the ability of remaining firms to be innovative.

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The golden age of American productivity growth followed what is called the second industrial revolution, in 1860-1900, which yielded a cluster of genuinely paradigm-shifting inventions: electric power, the internal combustion engine, modern industrial chemistry and telecommunications.

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They have displayed their results on an ingenious map of the industrial landscape, in which similar products cluster tightly together and unrelated products stand apart.

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More than that, fashion is just the sort of thing Britain is supposed to be good at in this post-industrial age: creative, high-value-added, cluster-based.

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For example, one company widely mentioned as a potential target of activists is Textron, the Providence, Rhode Island-based industrial conglomerate that builds everything from the V-22 Osprey tilt-rotor to smart cluster bombs.

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