  Reciprocal arcs represent the lowest order cycle possible to find in directed
graphs without self-loops. Representing also a measure of feed-back between
vertices, it is interesting to understand how reciprocal arcs influence other
properties of complex networks. In this paper we focus on influence of
reciprocal arcs on vertex degree distribution and degree correlations. We show
that there is a fundamental difference between properties observed on the
static network compared to the properties of networks which are obtained by
simple evolution mechanism driven by reciprocity. We also present a way to
statistically infer the portion of reciprocal arcs which can be explained as a
consequence of feed-back process on the static network. In the rest of the
paper the influence of reciprocal arcs on a model of growing network is also
presented. It is shown that our model of growing network nicely interpolates
between BA model for undirected and the BA model for directed networks.
