Figure 9

A comparison of the generated and theoretical marginal distributions of in- and out-degree under Krapivsky’s model. The model was parameterized with λ=3.5 and μ=1.8, and 10 networks with 10⁷ nodes were generated. We plot the degree distribution of a single example network. Three variants are investigated: The unaltered model (top), a model with Pareto-distributed fitnesses (center), and a model with normally distributed fitnesses (bottom). \(\alpha _{o} = \mu _{o} \pm 2 \sigma _{\textit {SE}} (\alpha _{o}^{*})\) specifies the inferred exponent of the marginal out-degree distribution, where μ _o is the observed mean of the exponent, σ _SE is the standard error, and \(\alpha _{o}^{*}\) is the predicted exponent for the unaltered model. The same form holds for α _i .