A reciprocity effect refers to the tendency for actors to reciprocate past
interactions. The statistic at timepoint t for dyad (i,j)
(tie-oriented model) or receiver j (actor-oriented model) is equal to
the number of (j,i) events before timepoint t. Note that a
reciprocity effect is only defined for directed events.
Optionally, a scaling method can be set with scaling
. By scaling the
reciprocity count by the indegree of the sender, the statistic refers to the
fraction of messages received by actor i that were received from actor j. If
actor i hasn't received any messages yet it can be assumed that actor i is
equally likely to receive a message from every actor and the statistic is
set equal to 1/(n-1), where n refers to the number of actors. The resulting
statistic is similar to the "FrRecSnd" statistic in the R package 'relevent'.