Fig 3. Estimation of Area—Population Scaling Relations for Regional Urban Systems.
Estimation of Area—Population scaling relations for: (A) England (red); (B) France and Belgium (blue); (C) Northern and Central Italy (green); and (D) Germany (yellow). The black line represents proportionate (linear) scaling; the yellow line the theoretical prediction where α = 5/6; and the red line the best-fit line from OLS regression of the log-transformed data.