MIT Press

Table 1.

Model parameters for collections of papers used in our measurements

Disciplines	Publication year T_publ	Number of papers N	Reference list length R₀	Growth exponents (α + β), yr⁻¹	Average fitness η₀	Shape parameter σ	Copying exponent γ, yr⁻¹	Indirect citations T₀	Nonlinear coefficient b
Physics	1984	40,195	19.2	0.045	0.48	1.13	1.2 ± 0.2	3.2	0.42
Economics	1995	4,782	8.8	0.12	0.49	1.13	1 ± 0.2	7.2	0.30
Economics	1984	3,043	8.4	0.09	0.45	1.13	1 ± 0.2	6.6	0.29
Mathematics	1984	6,313	3.9	0.092	0.46	1.13	0.8 ± 0.2	5.5	0.25

Disciplines	Publication year T_publ	Number of papers N	Reference list length R₀	Growth exponents (α + β), yr⁻¹	Average fitness η₀	Shape parameter σ	Copying exponent γ, yr⁻¹	Indirect citations T₀	Nonlinear coefficient b
Physics	1984	40,195	19.2	0.045	0.48	1.13	1.2 ± 0.2	3.2	0.42
Economics	1995	4,782	8.8	0.12	0.49	1.13	1 ± 0.2	7.2	0.30
Economics	1984	3,043	8.4	0.09	0.45	1.13	1 ± 0.2	6.6	0.29
Mathematics	1984	6,313	3.9	0.092	0.46	1.13	0.8 ± 0.2	5.5	0.25