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Equation 3 · Part 1 · Cities Are Organisms That Refuse to Die: Urban Evolution to 2100

Symbol Y

Y(N)=Y0 NβY(N) = Y_0 \, N^{\beta}
YY

What this part means

Y is part of the quantity the equation computes from the expression on the right.

Its job in the formula

Y is part of the quantity the equation computes from the expression on the right.

The passage around this formula

…tied to physical infrastructure scale sublinearly: length of electrical cable 0.87, road surface 0.83, gasoline stations 0.77, gasoline sales 0.79 [ 1 ] . In the compact notation the paper made famous, a quantity Y relates to population N as Y(N)=Y0 NβY(N) = Y_0 \, N^{\beta}. where β\beta ≈\approx 1.15 for the socioeconomic quantities and β\beta ≈\approx 0.85 for the infrastructural ones. A city twice the size of another does not simply have twice the patents and twice the roads; it tends to have somewhat more than twice the…

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A function assigns an output to each allowed input. The expression f(x) means “apply f to x”.

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