  Users of social networks display diversified behavior and online habits. For
instance, a user's tendency to reply to a post can depend on the user and the
person posting. For convenience, we group users into aggregated behavioral
patterns, focusing here on the tendency to reply to or reciprocate messages.
The reciprocity feature in social networks reflects the information exchange
among users. We study the properties of a preferential attachment model with
heterogeneous reciprocity levels, give the growth rate of model edge counts,
and prove convergence of empirical degree frequencies to a limiting
distribution. This limiting distribution is not only multivariate regularly
varying, but also has the property of hidden regular variation.
