Bettencourt等人在2007年的研究<ref>Bettencourt, L. M., Lobo, J., & Strumsky, D. (2007). Invention in the city: Increasing returns to patenting as a scaling function of metropolitan size. ''Research policy, 36''(1), 107-120.</ref>指出,城市人口规模(N)与发明活动(以专利数量 Y 衡量)之间的关系,发现两者同样遵循超线性幂律关系,其公式为: | Bettencourt等人在2007年的研究<ref>Bettencourt, L. M., Lobo, J., & Strumsky, D. (2007). Invention in the city: Increasing returns to patenting as a scaling function of metropolitan size. ''Research policy, 36''(1), 107-120.</ref>指出,城市人口规模(N)与发明活动(以专利数量 Y 衡量)之间的关系,发现两者同样遵循超线性幂律关系,其公式为: |