  In this paper, we analyze assortativity of preferential attachment models. We
deal with a wide class of preferential attachment models (PA-class). It was
previously shown that the degree distribution in all models of the PA-class
follows a power law. Also, the global and the average local clustering
coefficients were analyzed. We expand these results by analyzing the
assortativity property of the PA-class of models. Namely, we analyze the
behavior of $d_{nn}(d)$ which is the average degree of a neighbor of a vertex
of degree $d$.
