Basic properties of the PubMed (2003-2007) and USPTO (2003-2007) networks along with power-law fits of their degree distributions.

The power law distribution has the form , for , where x is degree, C is the normalizing constant ; n is the number of observations; and is the estimated lower bound (cutoff) of the scaling region such that . The values here were computed from 1,000 iterations of the non-parametric fitting procedure using the goodness-of-fit approach described by [58]. Because the p-value for each distribution is zero with large and small , we have strong evidence that none of the distributions fit a power law. (See also [59]).Note: Standard deviation shown in parentheses.