Clearwire is not building a nationwide system but will focus on large communities with population density where the bulk of the demand is centered.

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It predicts a rising global middle class, urban density increases, 50 percent growth in demand for food, water and energy, among many other results.

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While West has observed a positive power law in that the demand for roads and gas stations also decline as density increases, sooner or later that has to end.

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High population density, a poor ratio of available water to demand, and regional imbalances in available water supplies are serious challenges for China in managing its usable water supply.

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Yet strict density limits are preventing real estate developers from meeting the market demand for more housing and office space.

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